When a four-year-old evacuee returned to his Hackney home after fleeing the Blitz, he received a letter from the well-to-do prep school boy who had become his wartime best-friend.

But despite his mother’s insistence, Barry Spencer never replied. It was a decision he came to regret for more than 70 years.

As their lives took them in wildly different directions, Mr Spencer, now 75, made repeated attempts to track down his East Midlands-born pal, unaware that 76-year-old David Hurwich was doing the same thing.

Despite both living in London at one point, their hapless attempts at contact were thwarted by name changes, unrecognisable streets and around 3,000 miles of Atlantic Ocean.

But last week, at Leicester railway station, the city where they first met in 1942 — it was as if they had never been apart.

Instantly recognising one another, they embraced and shared memories that had developed over decades.

“I’ve always wondered what happened to David,” said Mr Spencer, who flew to the UK from his home in Agoura Hills, California for the reunion.

“One of the first things I did, when we got in touch, was apologise for not answering his letter. It was niggling at me for decades.”

The pair spent a day touring the city where their friendship had blossomed as boys. They visited the same synagogue at which they prayed and the grand Hurwich family home, which has since been converted into flats.

That had strong memories for Mr Spencer whose more modest background saw him living in a basement flat before his home was evacuated.

“Only the staircase was the same,” he said. “I remember it as being like a castle. I was sure a giant was going to eat me. They took me kicking and screaming inside. It had a queen-size bed. In Hackney I had a camp-bed.

“David taught me how to tie my shoelaces and what the word ‘boo’ meant. He was always more advanced than I was. He went to the local prep school, with a very nice uniform, and I went to the state school. But we were little boys. There is no class difference between little boys.”

Mr Hurwich, now a retired accountant, said: “For Barry, coming to us was a great change. Financially, it was very different to what he was used to. It was a big household, with a maid, cook and nanny.

“But we had good fun and got on well.”

The reunion was made possible after Mr Spencer, a semi-retired lawyer, finally decided to hire a researcher in December.

“I didn’t know if he was alive or dead. I started looking on the internet, made a couple of trips around Leicester, but I thought his surname was ‘Hurridge’,” he said.

“By some luck and inspiration the researcher got in touch with the local synagogue. A couple of days later, I woke up to an email from David. I couldn’t believe it.

“I called him and we spoke for around 45 minutes. We talked about our recollections, families and careers.”

Mr Hurwich had faced similar problems. He had been searching for a Barry Isenblatt — the family’s original name, later changed because of fears that it made them a target for antisemites.

“I had thought about Barry, but not with as much interest as him,” said Mr Hurwich, a Leicester Hebrew Congregation member. “I was surprised and pleased when he came to Leicester.”

Mr Spencer left the Hurwich family, who also looked after a German Kindertransport boy called Verner, after nine months as “things started to quieten down”.

Do they plan on staying in touch? They do. But they’re not planning to leave it another 71 years.