He joined Blue Peter in 1980, and shortly afterwards it was revealed in a tabloid newspaper that Duncan had appeared nude in the British film The Lifetaker (1975). That he was ever a porn star has been refuted by the BBC in The Times.
He ran in the first London Marathon in 1981 (in 3 hours and 10 minutes) and ran again in the 1991, 2001 and 2012 events.
Unusually, Duncan had two periods with Blue Peter, being on the team from 1980 to 1984, and again from 1985 to 1986. During his stay with the programme, he became associated with the kind of daredevil stunts previously popularised by John Noakes, and these continued in his own spin-off series, Duncan Dares. On 20 February 2007 Duncan was awarded the highest Blue Peter Award - The Gold Badge. This badge has been awarded in his role as Chief Scout of the UK.
Read more about this topic: Peter Duncan (actor)