Behind-the-scenes Harry Potter photos up for auction

Graham Wood took more than 140 photographs behind the scenes of five Harry Potter films

Behind-the-scenes photographs taken on the set of Harry Potter by the man who shovelled coal on the Hogwarts Express are set to go under the hammer.

More than 140 pictures, captured during five Harry Potter films, are expected to fetch between £2,000 and £3,000 when they go up for auction in Derbyshire.

The photographs were taken by Graham Wood, a retired railway worker from Buxton, who volunteered as a boilerman on board the legendary locomotive.

The archive has been described as "a real treasure trove for Harry Potter fans".

The collection includes a call sheet, signed by actors Daniel Radcliffe, Rupert Grint and Emma Watson - who played famous wizarding trio Harry, Ron and Hermione

Mr Wood said: "While cameras were banned on set, it was more a rule for the paparazzi than personal use and as time went by, it became more relaxed.

"I never appeared in the film, but I was behind scenes every time the famous locomotive made an appearance."

The collection features two call sheets, including one from the Harry Potter and the Order of the Phoenix film - signed by Daniel Radcliffe, Rupert Grint and Emma Watson, who played Harry, Ron and Hermione respectively.

Hansons Auctioneers, which is overseeing the collection, said a burgundy cap worn in the film by Frank Santrian - the driver of the Hogwarts Express - and a Hogwarts Railway insignia found discarded in one of the carriages also featured.

The 79-year-old added: "I can't say we mixed with the cast but those with an interest in steam trains like Mr Weasley [actor Mark Williams] would come down to the footplate for a chat."

Mr Wood volunteered as a boilerman on board the legendary locomotive

Mr Wood worked as a fireman for British Rail at Buxton, until steam trains were decommissioned in 1968.

He first came across the GWR 5972 Olton Hall locomotive - later reincarnated as the Hogwarts Express - during the 1990s, while working at the Tunstead Quarry in Derbyshire.

The locomotive, which had been saved from the scrapyard by the heritage rail operator West Coast Railway, was used for charter trips in the north of England.

Hansons music and memorabilia expert, Claire Howell, said: "From never-seen photographs and autographs, to worn clothing and call sheets, this is a real treasure trove for Harry Potter fans, added to which it comes from the most wonderful source."

The collection will go under the hammer at the auction firm's music and film and memorabilia sale on 17 September at its Etwall saleroom.