Brian Leveson is anxious. One of the most powerful judges in Britain is about to embark on an experience that he normally, studiously, avoids. He is about to be interviewed by a newspaper journalist.

This is the man, you will recall, whose 2011 Leveson Inquiry forced some of the most powerful, provocative and controversial journalists, media moguls and editors to reveal the innermost secrets of their trade, answer questions they’d never been asked, and at times to humiliate themselves. All of it in front of an astonished public, who watched the live, televised inquiry expose a culture of snooping into the lives of celebrities like Hugh Grant and J K Rowling; members of the public such as Madeleine McCann’s parents; and even the murder victim Milly Dowler.

Sir Brian himself has always refused to speak about how that experience affected him. Particularly when vociferous sections of the media castigated him for what many regarded as a naïve approach and an unnecessarily harsh crackdown on an already regulated industry tarred by a handful of malign individuals and, at best, incompetent managers.

He is obviously a tense and serious man; one of the more taciturn individuals I’ve interviewed. The start of our 90 minutes is punctured with hesitation, caution and a three-minute break while he reconsiders whether he should have agreed to the interview in the first place. Still, we proceed. Sir Brian, I soon learn, is a man of his word.

But even a few gentle questions elicit a lawyer-like defensiveness. Perhaps that is not surprising, given that he is being interviewed by a member of an industry that’s still wounded by his inquiry.

Just a few weeks ago, the press-backed Leveson’s Illiberal Legacy report was published and most newspapers warned that the judge’s recommendations posed an unprecedented threat to press freedom.

When I ask him about the repercussions of his inquiry, he responds: “What you are doing is persuading me that I should have never given this interview. I do not want to increase my profile.”

We could, I suppose, discuss his illustrious legal history and roles in trials such as those involving murderer Rosemary West and the killers of Damilola Taylor (eventually, we do). But it’s this line of inquiry that, obviously, most interests me.

“I just did what I was supposed to do,” he says. “I produced my report and it is there for people to talk about. I just get on with the job I’m doing.’’

Was he, I ask, emotionally wounded by headlines that appeared after his recommendations? Headlines that called him “Old liverspot” and “Incredibly naïve”; sketches that painted him as “Brian the Beak” or even a book by one Fleet Street veteran that compared him to King Canute, alleging he had tried “to stem the tide of free expression from sweeping on to the shores of Great Britain”.

“In terms of emotions, judges are no different from anyone else,” he says. “But I have found that I have been put under the spotlight as a result of the work I have done. People have come up to me in the street and shared their views. Not only in this country, but it has happened to me when on holiday in Italy and elsewhere. And I just cope with it. I have always preferred to remain comparatively under the radar, which has not been helped by the Inquiry of course.’’

Clearly Sir Brian, a contemplative and deeply private man, would rather the Inquiry be left to speak for itself. But that’s impossible when you step in front of the media’s glare and become a public figure yourself. Surely he can see how important it is to speak about it?

“I simply cannot talk about regulation of the press because, if I do, I dump myself into the middle of a political debate which is going on to this day,” he says. “There is supposed to be a second limb to the Inquiry which can only start when all the criminal cases have been concluded. [The report] could not go into who did what to whom because there were all sorts of prosecutions pending.”

You mean people like Rebekah Brooks (the former editor of the Sun and News of the World), I ask? What, I wonder, does he think of her resurrection as chief executive of News UK, the company she left in controversial circumstances, a company that was found to have used widespread phone-hacking — a practice which she was cleared in court of ever sanctioning or knowing about.

‘‘Tell me about it,’’ he says, his muttered words seemingly laced with sarcasm.

But he’s quick to remind me: “I know it has been three years since my findings were published but journalists are still being investigated. It is up to the government now. There will come a time when someone has to decide what will happen with the second limb of the Inquiry.

“I’ve done a report, it’s there. What has happened since its publication is for others to determine — not for me. It’s inappropriate for me as a serving judge to get involved in those kinds of discussions. I have to be very careful, because the one thing I cannot talk about is politics. I will not talk about issues of policies and law which might come up to me for decision, because if I did comment, someone would say to me: ‘Well you have got a pre-judged view’. There is a risk that by expressing a view on policy, judges disqualify themselves from a later challenge to that policy.”

That is partly why he has repeatedly refused requests to speak. Even his lecture on “Security and Justice’’ for the 13th Isaiah Berlin annual lecture at Hampstead Synagogue this month was free from any mention of press regulations. Doing so, he says, could affect any future hearing he is asked to sit on.

And this, I think, gets to the heart of Sir Brian’s character. On television, the 66-year-old appeared stern, eyebrows always furrowed, his hands cushioning his chin as he listened intently to emotive testimony from victims of phone-hacking and the bemused ramblings of uncomfortable editors not used to such cross-examination.

His intimidating, almost pontifical earnestness, though, belies a heartfelt passion for right over wrong and for the law’s ability to expose rule-breaking. His instinct is not to grandstand — even though the Leveson Inquiry did end up as a bit of a show-trial — but to follow the strict rules of the law.

Sir Brian, it turns out, is a man obsessed with the endless regulations and interpretations of law that can bemuse the rest of us.

“The law is a critical part of our society,” he says. “It must be valued and recognised. The practice of the law is equally a critical part of our society. I think there is a real concern about the future of the law in the face of diminished resources. As a society, we must encourage some of our best lawyers to go to criminal law, because it is actually important that the system works coherently and fairly, so we convict the guilty and acquit the innocent, and that requires capable lawyers doing the job.

“In law, you never stop learning and, more significantly, every case is different. The great thing about my job is there is no routine, the cases may look the same but they are all dealing with different people who rubbed against life’s problems in different ways. And that’s why I say that the job not only requires hard work, but humility. Everything you do affects somebody’s life and somebody’s liberties.

“The oath that I took was to do right to all manner of people after the laws and usages of the realm without fear or favour, affection or ill will. People say frequently that we judges do not live in the real world. It is true that I have had a tremendously privileged background and education; but my professional career has brought me into daily contact with people who have not had those advantages, who were struggling with enormous difficulties in their lives and who have had to confront those difficulties with as much fortitude as they could muster. That is a very humbling experience.”

It’s ironic, then, that his family wanted him to be a doctor. Born into a traditional Jewish household in Liverpool, Sir Brian, the middle child of three, idolised his father. The two looked alike and would spend their evenings having long talks. They would play golf together in Hoylake, the Merseyside seaside town where they would holiday every year with other Jewish families. His first real taste of the law would come when he accompanied his psychiatrist father to a mental health tribunal.

“I have no doubt that I have inherited the empathy my father had for people,” he says. “Sometimes, I swear in judges and I make the point of saying to them: ‘Being a judge not only requires continued diligence, but also humility’. The most important person in court is the person who is going to lose. They have to feel that they have had a fair crack of the whip; a fair trial.”

He attended cheder with his siblings and was barmitzvahed at the Childwall Hebrew Congregation, where he also sang in the synagogue’s choir. As a student at Liverpool College, he played bridge and competed in his school’s chess team.

“My childhood was normal,” he adds. “At least, I do not think there was anything exceptional about it.”

Bizarrely, considering what was to happen to his career, it was a TV show that changed his life. Boyd QC, a drama series starring Michael Denison about a London lawyer trying criminal cases in the 1950s, transfixed him and put him in direct disagreement with his mother, Elaine, who was determined he’d be a doctor like his uncle and father. “My mother was always keen that I become a doctor on the basis that, whatever happened, the world would always need doctors and you could establish yourself in any country as one.”

She persuaded him to take science subjects ahead of university. He conceded and was one of the few undergraduates to have sat Oxford University entrance exams in science, to secure a place on a humanities course. “I agreed to keep my options open,” he recalls. “If I would have suggested the same thing to my three children, they would have told me exactly what to do.”

Sir Brian — whose grandparents settled in Britain from Russia and Poland at the turn of the century — adds: “My mother was not worried about being in England, but she saw medicine as an easily transportable skill.” However, the law won out and he became the first in his family to pursue a legal career.

The Leveson family is extraordinarily close. His eldest sister Diane is a magistrate who still lives in Liverpool and his younger brother Clive is a doctor in Manchester. They’ve never spoken before about their brother, his career, the Inquiry and the devastating emotional impact it had on Sir Brian and the entire family.

Until now. From speaking to Clive, it’s abundantly clear that they have a great deal of love for each other, and that, despite the geographical distances, the bonds between the three of them (they lost their parents when the children were in their 30s) have been strengthened by Sir Brian’s torrid time in the spotlight.

“He was my big brother, he was lovely,’’ says Clive, recalling what it was like to grow up with his illustrious sibling. “He was a serious child and was one of those guys who, if he said he would do something, he did it and did it well. I had the problem of trying to live up to him — even if he wasn’t good at something, he was always a trier. He always worked hard at everything. He was no athlete but he tried. The one attribute he’s always had is he has always been an extremely hard worker.”

I ask Sir Brian what words he thought his siblings would to use to describe the character he had as a child. “Grey, hardworking and dull,’’ is his instant reply. Clive, however, sees it differently. “Studious,” he says.

From left: Hugh Grant, Rebakah Brooks and JK Rowling at the Leveson Inquiry

Smart, too. Clive is adamant that his brother knew he would bear the full force of the ensuing media wrath from the moment the inquiry was announced. “I think that is why he had the Inquiry televised,” he says.

“Otherwise, the only people who would be reporting on it would be the very people he was investigating — the press. And the press deliberately misinterpreted the whole inquiry to undermine everything. At no time was he talking about ‘government-regulation of the press’.

“I never got depressed about the attention. Half the time, the headlines were almost funny — especially when you know that the person they are describing in sketches is not the real person they are talking about.”

And does he think the coverage affected the real Sir Brian? “I do not think so. He knew what he was up against, he knew what was happening throughout and that was one of the reasons he presented his report and then chose to not discuss it — on the principle that the report stands as it is. He’s mindful that things can be taken out of context. That goes with his job as a barrister and a judge as well as doing the report.”

However, if the events didn’t have an overt emotional impact on the brothers, they most certainly did — and still do — on their sister Diane.

She cries several times during our conversation and she has to hold herself together, her voice regularly trembling, when she talks about how proud she is of Sir Brian’s achievements. “I am very proud of him,” she says. “Clive and I have been 100 per cent supportive of everything he has done.

“He is one of the kindest people I know. He is very supportive of anything that I have needed. The Inquiry affected me during the magistracy because all my colleagues knew he was my brother. People I worked with kept saying: ‘I saw your brother on TV’.

“It was most awful reading what the tabloids were saying about him because you just knew what they were saying was not true.”

His findings can be found in the 2,000-page report on the culture, practices and ethics of the British press, a report that cost the taxpayer £5.4 million. His family tell me Sir Brian worked night and day to produce the report and refused to take holiday — a “workaholic” trait he has held since childhood. Undaunted by the experience, Sir Brian has retained his post as president of the Queen’s Bench Division and continues to fight for the underdog — which is perhaps why he considers Shami Chakrabarti, a director of human rights group Liberty, a “great friend”.

It’s another trait he has inherited from his father. Perhaps that is why as an undergraduate he shunned the elitism of the Bullingdon Club and instead sat as president of the Oxford Law Society, joined the Jewish Society, and took part in a Crime and Challenge Club which looked at the social background of people who committed offences. “There were a large number of people from public schools at Oxford, but my friends were not of that ilk,” he says, rejecting any suggestion of the university’s ethos being that of an old boys’ club.

“Although there is a lot of publicity about the Bullingdon Club and all these rah-rah organisations, most of us were not involved in that sort of stuff at all. I am afraid I was rather grey at university, too. There was no easy path —I worked my socks off. I was quite studious, serious about what I was doing and I found it quite difficult to get into law, into humanities, having previously done science. I was more used to equations than writing essays.”

Upon graduating, Sir Brian planned to spend a year studying at a university in America. Then his father fell ill. It’s a testament to their relationship that he chose to take the English bar examinations so he could spend time with his family. He did not feel it appropriate to leave.

Aged 21, he was called to the bar. He admits certain chambers were well known for their opposition to taking young Jewish men and women to their sets at the time — ‘’I think there were sets of chambers where there was antisemitism, where it would have been difficult for me to get into.’’ But after he attended a mental health tribunal with his father, who had recovered, he met and found a placement with barrister Inge Bernstein at a Liverpool set which is now known as Atlantic Chambers.

Clive remembers his elder brother working late nights and long weekends as a young barrister. “He would work on a Sunday afternoon right through into the night,” he recalls. “The hours he would put in were enormous. He was getting more work and he was very conscientious.”

It is unsurprising that Sir Brian quickly rose through the ranks, became a QC and worked on the northern circuit, where he came into contact with some of the nation’s most harrowing cases. He is widely recognised for acting as lead prosecutor at the 1995 trial of Rosemary West, who murdered 10 women including her daughter. ‘‘That case was harrowing. If a normal murder is two or three dimensions, Rosemary West was five or six,” he recalls. “These girls had gone missing and their parents had not known what had happened to them for maybe 20 years. The parents had hoped that whatever they had done to upset the children, they were settled down and had happy lives; then they found out what had happened was worse than their very worst nightmares.” He recalls receiving a note from one victim’s parents — a card he still has today. “It said: ‘We only had one child, and the two people who have affected us most since we learnt what happened to our daughter are our family liaison officer and you’.”

He continues: “I have long since felt it appropriate that if I prosecuted a case, that I’d be prepared to talk to the family of the victim to explain what the issues were, what I was trying to achieve and give them a chance to speak to me.’’

Last week, the Lord Chief Justice warned that judges are facing increasing emotional strain from hearing sex abuse cases. So I ask Sir Brian whether cases like the West trial affected him emotionally? “Not really,” he says. “I have been doing this sort of work for a very long time. You get professional about it. You put aside the personal side of all this and you get on with the job. You do it intellectually and get on with it.”

In 1993, he moved to the Hampstead Garden Suburb home he still shares with his wife Lynne, whom he met back in Liverpool. Together, they are members of the local Orthodox synagogue. Now chancellor of the Liverpool John Moores University, his latest initiative is to reform the justice system in England and Wales to make it more technology friendly and less bureaucratic.

For some people, work is a chore. For others, it is a release. I suspect that Sir Brian fits into the latter category. How does he relax? “I did play golf before I got married, but I found that children and work and marriage didn’t permit much time for golf. Just family and certainly travel.”

Come on, there must be other things you enjoy doing — how about some of your favourite books or films? “I’m very keen to keep what is private as private as it can be.”

And, with that, my audience with the man tasked with identifying the difference between what should and shouldn’t remain private, bids me a cheerful farewell.

Well as cheerful as he can be.