A mongrel from Lewisham became a TV star and one of the nation's best loved dogs - thanks to a deception.

Petra - the Blue Peter dog for 25 years - was actually an impostor, a new book by the programme's former editor Biddy Baxter has revealed.

Shortly after a puppy was introduced to the programme in December 1962, the eight-week-old brown and black mongrel died of distemper.

Rather than traumatise young viewers of the BBC children's programme, the programme makers searched the pet shops of London for a replacement.

In her book, Dear Blue Peter, Ms Baxter writes: "We drove further and further away from Shepherd's Bush in despair and it wasn't until we reached Lewisham that we struck lucky.

"In a dingy shop window there was one small brownie-black puppy, shivering in the corner of a pen.

"It was a little bitch with pricked-up ears and a terrier-shaped muzzle."

The substitute, who was named Petra in a viewers' vote, made 1,222 appearances on the programme until June 1977.

  • Do you know anything about this doggy deception? Do you remember the dingy pet shop in Lewisham? Or share your recollections about Petra and Blue Peter, below.