The US military has dug up a farmer’s field in Essex to search for the remains of a Second World War airman who is unaccounted for after his plane crashed and exploded.

The B-26 Marauder bomber took off two days before D-Day on a mission to bomb a bridge in Nazi-occupied France, but experienced engine failure after leaving RAF Stansted Mountfitchet.

The twin-engined aircraft crash landed on June 4 1944, with its six crew and cargo of two 2,000lb bombs still inside.

The US aviator was lost in action after his aircraft crashed in early June, 1944 Credit: Gareth Fuller/PA

Four airmen managed to escape from the burning wreckage and survived, but a fifth died at the scene when the two bombs exploded.

His remains were recovered.

The sixth airman remains unaccounted for, and US military personnel from the Defence POW/MIA Accounting Agency are searching for his remains.

A marker points in a field near to Stansted Airport in Essex Credit: Gareth Fuller/PA

Sergeant First Class Peter Holderness, team sergeant, said the agency’s mission is to “find and retrieve our nation’s fallen service members and account for as many as possible”.

The agency requested that the precise location of the field in Essex remain secret so that trophy hunters cannot find it.

Items found by members of the excavation team Credit: Gareth Fuller/PA

It also asked that the airman’s name is not published out of sensitivity to his descendants.

Sgt Holderness said that “possible osseous material”, matter consisting of or turned into bone, had been found during the excavation.

Lab analysis is required to “verify what it actually is”, Sgt Holderness said.

Brian Seymour of the United States Department of Defence, at work Credit: Gareth Fuller/PA

If the initial dig fails to locate the airman’s remains, a permit could be sought to return for a further dig.

The agency did not specify the precise length of the initial dig, which concluded in August.

During the dig, a 23-strong team sifted through excavated soil at a “wet screening” tent, using hoses to find items of interest among the dirt.

There are 23 people involved in the work Credit: Gareth Fuller/PA

These were placed in buckets and then inspected further, with any bone matter or “material evidence” such as a dog tag or rings to be sent to the agency’s lab in Hawaii.

The agency said any finds will be notified to the authorities.

If the remains of the sixth airman are found and identified, his descendants will be notified, the agency said.

The next steps would be in line with the family’s wishes, and the airman could be reburied at Arlington National Cemetery in Virginia, which is the final resting place for thousands of America’s service members.

The excavation in Essex is the agency’s first in the UK, and a spokesman said there are 140 cases involving unaccounted-for Americans in the UK from the Second World War.

The items have been cleaned by the team Credit: Gareth Fuller/PA

There are 82,000 unaccounted for US military personnel from all past conflicts worldwide, the agency said, with just 206 of them identified last year.

The majority of the agency’s digs have been in south east Asia, including Vietnam and Laos, as the acidic soil has made many cases time critical as remains deteriorate more rapidly, a spokesman said.