The sample of Hitler’s hair which Channel 4 paid Holocaust denier David Irving more than £3,000 for, has been revealed as a fake.
The Channel bought the sample for its documentary series Dead Famous DNA, but said tests had shown it was not authentic.
In a report in the Radio Times, David Glover, Channel 4’s head of specialist factual programming, said it was not clear if Mr Irving had known the hair was not Hitler's.
"Whether he knew what he was selling was fake or not, we don’t know,” Mr Glover said.
“He may have sold it in good faith, but what we can say is all the evidence suggests that the hair he claimed was Adolf Hitler’s, our DNA science strongly suggests it wasn’t.”
The channel said it has not asked Mr Iriving to return its money.
Parliamentarians and communal groups had condemned the channel’s decision to buy the sample.
Gillian Walnes, founder of the Anne Frank Trust UK, said: “The fact that Channel 4 have chosen to pay the notorious Holocaust-denier David Irving the sum of £3,000 demonstrates the sensationalist and poorly conceived intentions of the programme makers.”
Mark Gardner, director of communications at the Community Security Trust, said: “It is distasteful to see Hitler being sensationalised, but even worse that David Irving – of all people – ought to profit from it in this way.”
He added: "It is hard to be surprised by this latest development.”
On Dead Famous DNA, aired on Wednesday, Mr Irving insisted that the sample was authentic.
Channel 4 previously claimed that the sample was gathered by Hitler’s barber, with sticky tape on the bottom of his shoe.