Can you help uncover the secrets of Ypres?

Ninety years after the battle of Passchendaele, known officially as the third battle of Ypres, a group of mud-splattered enthusiasts are trying to dig up some of the key trenches of World War I. And the BBC needs your help.

Geophysicist Malcolm Weale is a battlefield detective who specialises in uncovering history that has lain hidden for generations - in this case the shelters and deep bunkers that protected troops from the hail of explosive.

The farmland around the Belgian village of Zonnebeke was laced with the trenches that saw horrific casualties. Tens and thousands of men spent much of their lives and deaths underground - as evidenced by Malcolm's metal detector which picks up the metal fragments of shells and equipment turned up by ploughs every spring.

But Malcolm and the archaeologists who called him in are looking for one particular treasure - the Vampire Dugout, which was held by the Allies until the 1918 German offensive, briefly occupied by German forces, and recaptured by the British at the end of the war. Flooded, buried and forgotten after the war, it has not been entered in nine decades.

The men leading the search, including Peter Barton, a British historian who has written several books on the subject, have spent years delving into the history of the tunnels and the engineers who dug them. Working from the original trench maps, the Vampire Dugout, which was built 90 years ago by the British during the Battle of Passchendaele, would have housed a senior officer and up to 50 men.

The units that operated there were: 100 Brigade, 33rd Division,16th King's Royal Rifle Corps, 9th Battalion Highland Light Infantry Regiment and 2nd Battalion Worcestershire Regiment

But what really excites the archaeologists is the fact that the tunnels will be full of water, so the lack of light and oxygen will mean that anything left in the dugout is perfectly preserved - beds, weapons, clothing, and personal possessions. This gives the whole war a unique hands-on feel - the team will actually be touching and smelling a remarkable piece of history, providing a real sense of the daily routine 90 years ago.

They hope that the items they find will provide clues to the units that served there, and eventually to the personal stories of individual soldiers.

BBC News is particularly keen to hear from people who had relatives serving with the regiments mentioned above. Do you have their diary or letters describing the trenches and life in a dugout? Or any photos?

Send stories and photographs to: yourpics@bbc.co.uk or text them to 07725 100 100.