A Holocaust survivor has described the moment he came face to face with a former SS guard who is on trial for war crimes.

Ivor Perl, 83, said the experience of giving evidence at the trial of Oskar Groening had lifted "a burden off my shoulders".

Known as the "book-keeper of Auschwitz", Groening was responsible for sorting through prisoners' belongings and sending their money to Berlin.

He is on trial for contributing to the murder of 30,000 Jews.

Hungarian-born Mr Perl, who refused to speak about his war experience for more than 50 years, said taking part in the trial last month had helped him find closure.

"It was something I needed to do, to confront an actual person, to see someone as a human being," the great-grandfather explained.

But Mr Perl, of Buckhurst Hill, Essex, had to be persuaded by the prosecuting lawyer to give evidence after learning he would have to travel to Germany to testify. His family convinced him to take the opportunity.

He was 12 when he was deported to Auschwitz along with his parents and eight siblings. Only he and his brother survived the war. They later settled in Britain.

In the courtroom Mr Perl had the opportunity to address Groening. "As I looked at him, my first thought was pity. Pity for myself. After my testimony I said to the judge I would like to address a few words to the accused.

"I said when I look at you I can't call you 'Mr Groening' - because I couldn't bear the thought of calling him 'Mr', or a gentleman. I said to myself, are you the one that I've lost all these nights' sleep for, you're the one who put me through all that trouble?

"I thought, how could I have wasted all that energy on you?"

Groening, 93, admitted he was "morally guilty", when his trial began in the presence of almost 70 Holocaust survivors and victims' relatives in court in the north German city of Lueneburg in April.

Mr Perl added: "Before the trial I thought I would run over and spit in his eye. But I didn't feel like that at all.

"At times I felt as though I should feel more hateful and revengeful but it just didn't come.

"I give talks to schoolchildren but hate and revenge never come into the equation."

Mr Perl said the verdict was unimportant to him as punishing Groening would not ease his own pain, but he highlighted the global coverage of the trial as an important aspect.

Mr Perl was once reticent to discuss his family history, but he first spoke about his Shoah experiences at his synagogue in Essex after a last-minute cancellation meant there was no survivor for a VE Day commemoration ceremony.

In the 20 years since, he has spoken at schools and memorial events, supported by his wife, Rhoda. But the couple's advancing years and health concerns mean Mr Perl is considering stopping the efforts.

He intends to return to Germany for Groening's sentencing, expected to take place in July.