A HUGE green hoarding over the railway tracks near Didcot Parkway station has posed an eye-catching puzzle for passing Rail commuters.

It’s a mystery Sherlock Holmes, Britain’s greatest fictional detective, would have liked to get his teeth into.

But puzzled passengers can now put their minds at rest.

Didcot Railway Centre is being turned into a film set for a sequel to last year’s Sherlock Holmes movie starring Robert Downey Jr and Jude Law.

The green boards are needed to block out the Ladygrove estate, north of the railway line, with the film-makers planning to graft on a backdrop depicting Victorian London using computer trickery.

Security at the centre is now tight and the attraction will be closed to the public for the next two weekends.

Richard Hawkes, assistant manager of the Prince of Wales pub, opposite the railway station, said: “We got a letter warning that our customers might hear some bangs and explosions and that we shouldn’t worry, because they’re working on the new Sherlock Holmes film.”

Bemused train users were stunned to be told of the town’s small role in movie history.

Tim Phelan, a train manager for First Great Western, said: “I saw the first film and I thought it was very good.

“I’ll be looking out for the Didcot locations when the new film comes out.”

Sarah Danielle, 22, from Bristol, who was catching a train at Didcot Parkway, added: “I love Robert Downey Jr. This is exciting news for Didcot.”

The new movie, which is due to be released in autumn next year, is directed by Guy Ritchie, who also directed the first movie and is best known for the gangster film Lock, Stock and Two Smoking Barrels.

Robert Downey Jr and Jude Law will reprise their roles as Sherlock Holmes and Dr Watson as they face rival, Professor Moriarty.

The film will also star Stephen Fry as the detective’s older brother Mycroft, Jared Harris as Moriarty and Geraldine James as Mrs Hudson, the detective’s landlady.

The first film was nominated for two Oscars.

Film crews regularly visit Didcot Railway Centre, with more than 100 dropping in over the past 25 years.

Over the past 40 years it has being used as a set for scenes in Carrie’s War, the Channel 4 drama The Camomile Lawn, and Beyond Narnia, about Oxford author CS Lewis.

The centre still boasts a Great Western Railway steam locomotive shed.