He sold 100 million records worldwide. Frank Sinatra called him “The singer’s singer”. Yet Matt Monro, who died in 1985, aged just 54, never courted the trappings of celebrity and preferred a quiet life at home with his family.

He had hit after hit including Born Free, Portrait of My Love and From Russia With Love, most recently used as the BBC’s World Cup theme. But not many people knew that this very humble superstar was he was married to a Kindertransport survivor and that his son had a barmitzvah.

That son, Matt Monro junior, is now the same age as his father when he died. “My mum, Mickie Schuller, lost a lot of her family in Berlin,” he tells me. “She got evacuated on the Kindertransport to England with her brother.

“So yes, I’m Jewish, I had a barmitzvah. We lived in North London and I went to Golders Green Synagogue from the age of 11 to about 16. The reason I loved going was the youth club, we all used to play football.

He was never Orthodox, he says. “We were brought up to believe in whatever gets you through life. I never had any pressure on me to do anything. That said, I’m very proud to be Jewish.

“One of the reasons I’m proud is because of my mum’s upbringing and what she went through. I’ve still got my kippah and my shawl.”

Mickie Schuller was originally called Renate Annette Daisy Schuller born in Berlin on July 19 1933 during the early days of Hitler’s’ dictatorship. Two years later, her parents, Evelyn and Adolf, had a son, Ernest. The children’s maternal grandparents had left Berlin some 40 years earlier. As the Nazi regime took hold, the Schullers made the decision to send their children to their grandparents in England. Arrangements were made to send the two, Renate then five, and Ernest, just two and a half, on the Kindertransport.

On December 30 1938, the Southampton boat train brought 41 refugees to London. They had sailed from Hamburg on the SS Washington. Arriving at Waterloo Station, young Ernest was in tears until grandparents Anna and Max Halle carried them home to Acton. At the time, the Daily Herald ran the story of the children’s arrival with photographs showing the children bereft and bewildered, like parcels with tags around their necks.

Young Renate was devastated by the suffering her family had endured; the image of her father riding one tram after another to avoid being home when the Nazis came was etched permanently on her mind. Several members of the family had been gassed or shot. Her one last haunting memory before leaving Germany was of people running for their lives as her Uncle Freddie, her father’s brother, was dragged away from home to be shot.

Amazingly three months later, the children’s parents managed to escape Germany and the family were reunited until Renate’s father was picked up for interrogation, and held in an internment camp on the Isle of Wight. For the year he was held, Renate cried herself to sleep every night. On his release, unable to practice as a dental surgeon as in Germany, he set up a business as a dental technician making dentures.

When Renate started St Augustine’s Priory School in 1939, aged six, she could not speak a word of English. By the 1950s, she was working in Soho at music publisher Arcadia as a switchboard operator. Her boss, Harry Ralton, nicknamed her Mickie after Micky Mouse and the name stuck. Eventually she worked her way through the booming music business of the 1950s and became the first female plugger in the industry. That’s how she met Matt Monro, a former road sweeper and bus driver, who became one of the most popular singers of his day.

Their son, Matt junior, has toured the world keeping his father’s legacy alive. His own story is as remarkable as Monro senior’s rags to riches tale. He’s a huge star in the Philippines, where crowds of people meet him at the airport. One of his biggest fans is the former First Lady Imelda Marcos, whose husband was ousted as president in a popular uprising. Marcos is now back in the Philippines and has been to three of Monro’s concerts. “She’s a fascinating lady, not everyone’s cup of tea,” says Monro jnr. “She’s a strange woman, very intelligent though. I first met her when she had arranged to come up on stage at the end of show. I was taking my bow; she came up and thanked me. She walked up the steps and gave me a hug. My first words were ‘Alright, love?’ I gave her a kiss on both cheeks then sang a duet with her; we did Memories.”

As a young boy, Monro had no idea his father was famous. It was just normal to see his dad singing on stage. Nor did he realise that visitors to their family home including George Martin, Paul McCartney (McCartney wrote Yesterday for Monro snr) and Morecambe & Wise were anything other than family friends.

It was only when he was 13 and Eamonn Andrews surprised his father on This Is Your Life ( guests included Sammy Davis Junior) that young Matt realised the enormity of his fathers’ fame. “I used to see Dad perform wherever we went but as a young kid I didn’t know any different, I just thought that was what he did. He goes on stage and sings, that’s his job. People came up for photos and autographs etc but at a young age, I didn’t know that was any different to anyone else! This Is Your Life made me realise my dad was not just an average guy”.

Initially Monro wanted to be a golf professional. When he was 19, he was playing in the US Championships and Monro senior dropped everything to go and caddy for his son.

Sadly, not long after that Monro died from liver cancer. “I was an assistant professional with Crystal Lake Country Club in Illinois. After Dad died I came back to England to be with my mum and family. I never went back to the golf because what I realised was the reason I loved golf was because I used to play with my dad; that was when I had him to myself. The most special times in my life. I couldn’t go back to being a golfer after that.”

He began his own professional singing career began by accident after he was asked to sing at one of the many functions he attended to support cancer charities. “To be honest, until six years ago, I was rubbish” he says frankly. “First of all I used to be physically sick every time I went on the stage, from the pressure of people expecting me to be my dad.

“I always had charisma and stage presence but never had the voice. But I learnt my craft and I’d say that by a few years ago, my voice had improved. I never wanted to be a singer and have been one now for 31 years!”

He sang just once on stage with his father when he was 13. Subsequently, thanks to the wonders of technology, he recorded an entire album of songs duetting with his father.

“We were down in Great Yarmouth for the summer season. Without warning on his final night, he got me on stage to sing a song with him. I’ve never been so frightened in life because I looked at him on stage and for the first time in my life I realised he wasn’t my dad but Matt Monro. I can’t explain that. We sang Yesterday as a duet, I was petrified, my voice was breaking. I got through the song, it was the greatest night of my life. Unfortunately that was the only time I shared a stage with my dad. No one can ever ever take that away from me.”

This autumn he is embarking on the final tour, The Matt Monro Story, a two hour show of words and music, scripted by his sister Michelle. After that, he will retire from show business wanting to spend time with his new wife Chandrika, whom he describes as the love of his life.

“I do every single hit Dad had and share my own memories. It took two years to put it together. It’s the fourth year we’ve done it but the final one, goodbye. I can promise you I will never want to step on a stage again!”

The Matt Monro Story tours the UK from September 25 to November 22. www.atgtickets.com/shows/the-matt-monro-story/