BLUE Peter daredevil Peter Duncan was completely unaware of his family ties to the North-East until just over a decade ago when a totally unknown half-sister from Whitby, called Jennifer, got in touch with him.

“She’d been told by her mother that she had a brother who was ‘somewhat famous’,” says the actor/presenter currently touring to York in the musical Million Dollar Quartet.

Duncan’s father worked on Redcar sands in a show called The Wavelets just after the Second World War. “He met and fell in love with a local girl and they had a baby girl. She was adopted because my father and the woman were not married, but he never told us anything about it.

“Then he died, and the first I knew about it was when the daughter contacted me through a mediator because she was worried that a celebrity might not be interested. I was on it like a flash because I thought it was a brilliant story... and there’s 20 of this branch of the family coming to see the York show on the Friday night. A lot also came to see Birdsong (the First World War-era play) when I toured in that to York. They all cried at that one, so I’m hoping they sing along to Million Dollar Quartet because it’s not so tragic.”

Duncan doesn’t see his long-lost half-sister as Who Do You Think You Are? territory mainly because the Redcar relationship happened before his father and mother met.

“In those days if you had a baby out of wedlock it was often adopted because society frowned on such things,” he says. Duncan is saddest about the fact that he didn’t meet Jennifer’s mother before she died.

Since he shot to national fame in 1980 as a Blue Peter presenter, Duncan has maintained a reputation for switching between risky projects such as The Games and Tumble to the serious world of theatre with roles in Macbeth and Birdsong mixed with holiday documentaries.

His exploits in the auction room have been less successful. Celebrity Antiques Roadshow on BBC2, which was repeated recently, pitched him against former BP colleague Sarah Greene. The pair made record losses on £400 lots of purchases with Duncan particularly coming to grief over two fertility statues, a Pinocchio puppet and a woodburning fire.

“People told me I behaved very badly on the show. My wife is a midwife after all, and I didn’t know the fertility statues were recently carved. I thought they were ancient. The auction house was terrible because I had expected something slightly more upmarket. Maybe I got what I deserved.

“I spent more than I bought. I got the statues because the auctioneer bought them out of sympathy and, later, sold them back to me. I also ended up with Pinocchio because people seemed to keep buying my items after feeling sorry for me. What I didn’t realise is how many high-falutin people appear on these celebrity specials,” Duncan says.

Currently, he’s returned to the role of legendary record producer Sam Phillips who forged the careers of four US music legends: Elvis Presley (Rhys Whitfield), Jerry Lee Lewis (Martin Kaye), Johnny Cash (Robbie Durham) and Carl Perkins (Matt Wycliffe).

“I did it earlier this year for a few weeks and coming back to share tour dates with Martin Kemp. This is very much a play as a jukebox musical and, in fact, the play leads the story and you get to know about Phillips and how all these people came to him. They wanted to be one thing and through skill and imagination he turned them into something else.

“He was the catalyst creating huge stars which the record companies paid big money for. Phillips started off as a radio man but decided he wanted to record records and had a real skill in creating the sound. When you listen to the Sun Records tape there were about 20 or 30 people who could have made it big. Phillips was into recording black artists as well because he knew that was where the music was coming from. White kids were going into record stores to buy music that was, secretly, made by black people.”

Duncan went to a National Theatre voice coach to establish his US southern drawl accent for Phillips “similar to Bill Clinton, but nothing like Deputy Dawg”.

“In the play he’s a good businessman and puts a lot of effort into building a studio at an old autoparts store. He was very successful with Carl Perkins and Blue Suede Shoes and then people keep turning up at his door saying, ‘Make me a star’, including Elvis, Jerry Lee Lewis and Johnny Cash. Phillips was a plugger which meant once he had a record he would drive all over the US to plug it to radio stations. He talks about regularly driving 1,000 miles to find a DJ and say, ‘Play this’. He and his small team did everything. So, when Elvis turns up singing Gospel songs and wants to be like Dean Martin, he got him to do something different.”

Duncan’s three children have all got involved in theatre – “but I managed to talk them out of acting” – and he has just performed in an Edinburgh play written by his daughter.

“It is a short piece called The Dame and really is about life in North-Eastern towns with all the research being about my parents. My father returned with his show to Redcar in the 1950s. In their heyday these Northern coastal towns were full of people and it was a very poetic piece and got lovely reviews. The North-East coast was like the Edinburgh Festival is now in terms of appeal. Saltburn, Scarborough, Filey, Whitby and Bridlington were all great places to go in the summer, but sadly no longer. In our story, some of the memories were based on when my father tried to revive the show in about 1959 to 1960, but there was nothing there,” Duncan says.