One of the distinctive white racing helmets worn by The Stig on BBC's Top Gear could fetch up to £1,200 when it is sold at auction today.
It is being sold by Sophia Vaizey, who was given the helmet as a leaving present after working on the show as a production co-ordinator for 18 months.
One of the programme's presenters, Richard Hammond, signed it, along with production crew members and The Stig himself, who has now left the motoring show but wore it between around 2002 and 2005, Mrs Vaizey said.
She hopes the helmet will sell for more than the guide price after the recent, highly publicised High Court battle involving the BBC over the disclosure of The Stig's identity.
Mrs Vaizey, 30, from Hove, East Sussex, said: "Selling the helmet has been something that has been on my mind for a while.
"But I'm looking to buy a house and this has been stored in a cupboard at my mum's house while I have been travelling around and living in different places.
"I'm quite a sentimental person and I don't want to let go of it, but as my family have said to me, it might not be worth anything in 10 years' time."
She went on: "The Stig wore that one on the show for quite a while. He then got a new one for safety reasons, so it got stored away in the Top Gear office.
"I was quite surprised when they gave it to me but also I felt honoured."
The BBC recently took legal action to block publication by HarperCollins of an autobiography which would unmask the show's mystery driver.
But after more than a day of legal argument in private, Mr Justice Morgan said he would not grant the BBC a temporary injunction as he said racing driver Ben Collins identity was already widely known.
It had been a badly kept secret for some time, having already been published in the media last year.
Collins has since joined rival show Fifth Gear on Channel 5 where he will appear without his trademark helmet.
The helmet will be auctioned at Gorringes Auctioneers in Lewes from 6pm.