FIVE German prisoners of war spent weeks tunnelling out of the place, leading to a famous film being made about their exploits.

But many people do not realise the history behind Hayes Conference Centre, near Swanwick, which was turned into a makeshift prison camp during the Second World War.

Now, as the venue prepares to celebrate its 100th anniversary, it has emerged that the tunnel the Germans used to escape is still intact.

Brian Cupples, general manager of Hayes, said: "Few know the place was requisitioned as a major PoW camp in World War Two.

"All five were recaptured, but Luftwaffe fighter pilot Franz von Werra escaped again, from Canada, and made it back to Germany– the only PoW to do so throughout the war."

Von Werra's escape from The Hayes, known at the time as Camp 13, is featured in the classic 1957 war movie The One That Got Away. Hardy Kruger had the title role.

The pilot was shot down during the Battle of Britain and captured. He was sent to Swanwick as it was seen as more secure, after he broke out of a camp in Cumbria.

At Hayes, von Werra and four others spent a month digging a tunnel, which was finished in December 1940. The camp forgers equipped the group with money and fake identity papers. They slipped out under the cover of anti-aircraft fire and the singing of the camp choir. While von Werra's sidekicks were captured, he made it to Codnor Park railway station, where he impersonated a crashed Dutch pilot. He was finally caught at RAF Hucknall and returned to Swanwick.

Sent by ship to Canada in early 1941, and still determined to get free, he jumped from a moving train in Nova Scotia. Trudging through snow, he finally reached the United States – at that time still neutral – where he claimed asylum and was put on a ship back to Germany.

Von Werra returned a hero but was sent to the Russian Front, where his luck ran out – he was killed in action in 1941, aged 27.

The Hayes Conference Centre is this year celebrating a century as a Christian retreat.

Later this month, Terry Waite, an envoy for the Church of England who was himself held captive in Lebanon, between 1987 and 1991, will attend a special service of thanksgiving. Visitors will be able to view the PoWs' tunnel.

Mr Cupples said: "Our PoWs may have been unwilling guests but visit any community in the UK and you'll find people who have enjoyed a time of refreshment here."

The conference centre was originally built as a private house in the 1860s by entrepreneur Fitzherbert Wright. Its conservatory is reminiscent of St Pancras station – Wright built both.

As a conference centre, it offers residential and day facilities for up to 400 delegates, with almost 40,000 people a year passing through its doors.

Thankful visitors, including several bishops, have written to The Hayes in recent weeks in light of the centenary.

Among them was the Archbishop of Canterbury, Dr Rowan Williams, who said: "The Hayes has been a valuable resource for quiet reflection and recharging of batteries.

"I hope it will continue to play its important role in Christian life."

Tony Travis, head garden at Hayes, has been into the tunnel.

He said: "Considering how old it is it's in quite good condition.

"There are a few tree roots poking through and it can be a bit claustrophobic but it's holding up well."