A swagger stick that belonged to WW2 Great Escape hero Marcel Zillessen has been found at the back of an airing cupboard after 20 years.

A militaria expert was stunned to make the find as the world marked the 80th anniversary of the Great Escape, the most famous prison break of all time.

Matt Crowson, head of militaria at Hansons Auctioneers, said: "Incredibly it was discovered at the back of an airing cupboard in the South Derbyshire village of Ticknall - but only because a plumber had been called to fix the boiler! It had lain there for at least 20 years, long forgotten.

"What a find to make. Though unconnected to Zillesson's WW2 service as an RAF pilot officer, it belonged to him when he attended Gresham School OTC (Officer Training Corps) as a teenager from 1930-33.

Matt Crowson, head of militaria at Hansons Auctioneers

"His swagger stick, a short crop usually carried by a uniformed person as a symbol of authority, is a memento of a man who will never be forgotten thanks to his role in the Great Escape from Nazi prisoner of war camp Stalag Luft III. His part, an important one as he could speak fluent German, was portrayed by James Garner in the 1963 film of the same name.

"Zillessen was due to be the last man out of an escape tunnel called Harry. He never actually made it, though that ultimately saved his life. He passed away just one week short of his 82nd birthday. Of the 76 who did escape, most were captured within three days and 50 were executed on Hitler's orders. Only three got away."

The seller said: "The swagger stick came from my mother-in-law's friend in the 1990s. It was her late husband's. Whilst visiting her with my eldest son, then a tot, she gave it to him to play with. I guess she had no use for it.

Journal of RAF Flight Lieutenant Viv Phillips, an inmate of Stalag Luft III prisoner of war camp, sold for £13,500 at Hansons Auctioneers

"I really can't remember how long my children played with it. On reflection I'm surprised it survived at all. At some point it would have been put away somewhere in the house and forgotten. It recently turned up at the back of the airing cupboard. I had to empty some contents so the plumber could fix the boiler and it was standing in the back corner. I'd say it had been there for at least 20 years.

Matt said: "We speculate the man who originally acquired the swagger stick knew Zillessen at Gresham School Officer Training Corps in Norfolk. We also think he may have worked with WW2 Allied code-breakers at Bletchley Park. Perhaps Zillessen gave it to him as a memento of their friendship.

"Whatever the circumstances it is amazing the swagger stick turned up as the world marked the 80th anniversary of the Great Escape. The Nazis thought Stalag Luft III prisoner of war camp was escape-proof but on the night of March 24/25, 1944 some 76 Allied airmen proved them wrong - including Zillessen. The major WW2 act of defiance is regarded as a sign of hope in man's darkest hour."

Zillessen (1917-1999) was born in Northampton to a German father and Irish mother. He attended Gresham School in the early 1930s and was a member of the Officer Training Corps from the age of 13-16. It's unknown what rank the young Zillessen held during his time in the OTC, but his swagger stick was used during his time there.

He studied at university in Berlin and became a fluent German speaker, a skill that paid dividends as a PoW. In 1943, while piloting a Hurricane in North Africa, his plane was shot down. Zillessen ended up in Stalag Luft III, which held allied Air Force personnel.

His fluency in German helped him gain favours from his captors. They provided him with pens, paper and ink that were later used to forge travel documents. He was instrumental in planning the Great Escape, using tunnels known as 'Tom, Dick, and Harry'. It's well documented he was due to be last man out from the Harry tunnel. Ultimately the plot was foiled and he fled back to his barracks when the tunnels were discovered.

His 70.3cm long swagger stick has a lacquered malacca cane body, brass ferrule and nickel pommel. The pommel bears the badge of Gresham School OTC (Officer Training Corps) and the name 'Zillessen' is scratched into both the metal of the pommel and the wood. Also visible are the words 'Gresham' and 'Holt', the latter being the location of the Norfolk school. The find enters Hansons' May 15 Medals and Militaria Auction with a guide price of £100-£150.

Matt said: "The estimate may appear modest but the memories it's likely to unleash will be monumental. Had the piece have been connected to Zillessen's wartime service and the Great Escape it would be worth much more, but this is a pre-war piece from his teenage years in a school officer training corps. Nevertheless, thanks to the impact of the Great Escape, the find may surprise us all under the hammer."

In 2019 a diary penned by RAF Flight Lieutenant Viv Phillips, an inmate of Stalag Luft III prisoner of war camp, sold for £13,500 at Hansons Auctioneers. As well as anecdotes, sketches, cartoons and poems, the journal contained black and white photos of men held in the Stalag Luft III camp – the characters who played their part in one of the greatest prison escapes of all time.