A lost squadron of Second World War Spitfires, the iconic fighter designed and built in Southampton, has been unearthed in South East Asia after being buried and forgotten for almost 70 years.

The discovery, described as “enormously significant and important’’, of 20 Spitfires has emerged after years of research and exploration in Burma.

Already aviation experts from Southampton’s Solent Sky Museum have contacted 10 Downing Street, after Prime Minister David Cameron held talks with Burmese leaders and raised questions about bringing the Spitfires back to the UK.

Eventually the aircraft, still to be recovered, could be assembled and then flown for the first time, after being entombed for 67 years.

Today only a handful of Spitfires, worth anything up to £2m each, remain in flying condition.

Hidden below ground in an old bomb crater, the fighters have yet to be fully examined but it is hoped they are still in pristine condition, protected by purpose-built cases and wrapped in waxed paper.

The exact location of the burial site is being kept a closely guarded secret but it is known the Spitfires were sent out to Burma only weeks before the end of the war.

Just before America dropped the first atomic bomb on Hiroshima, Earl Mountbatten, then supreme allied commander of South East Asia, ordered the Spitfires to be buried in Burma.

Although the Japanese forces had fled, Earl Mountbatten was anxious that the Spitfires could be used against the allies should a successful reoccupation take place.

Secretive Solent Sky Museum director, Squadron Leader Alan Jones said: “At first it was thought these Spitfires could have been built in Southampton, but now it seems they are of a later type, probably constructed at Castle Bromwich.

“Many of the components used in the fuselage and wings found in the crates would have been put together in Southampton in various factories and workshops during the war.’’ The quest to find the lost Spitfires was led by Lincolnshire farmer, 62-year-old David Cundall, who spent a total of 15 years travelling between Britain and Burma.

He also placed adverts in various military magazines to try and trace former wartime servicemen who might have clues as to where the Spitfires were buried.

During this time Mr Cundall established contact with Burma’s secretive military government and gained permission to undertake his search for the Spitfires.

Visiting Burma at least 12 times, Mr Cundall finally located the Spitfires using sophisticated radar technology provided by Leeds University.

“We sent a borehole down and used a camera to look at the crates,’’ Mr Cundall said. “They seemed to be in good condition but in 1945, Spitfires were ten a penny.

“It was a typical British solution: ‘Let’s bury them, lads’.’’ During David Cameron’s recent visit to Burma, the Prime Minister secured the historic deal, which will see the aircraft dug up and shipped back to the UK.

A Downing Street spokesman said: “The Spitfire is arguably the most important plane in the history of aviation, playing a crucial role in the Second World War.

“It is hoped this will be an opportunity to work with the reforming Burmese government to uncover, restore and display these fighter planes and get them gracing the skies of Britain once again.’’ The recovery of the aircraft and shipment back to the UK is being backed by the Boultbee Flight Academy, which is based at Goodwood, and specialises in teaching pilots how to fly Spitfires.

Conceived by the design engineer R. J. Mitchell, pictured, at the Supermarine Aviation Works in Woolston, Southampton, the Spitfire became the symbol of the nation’s dogged determination during the Second World War when pilots fought and won control of the skies during the Battle of Britain. Throughout the conflict the Spitfire became the backbone of RAF Fighter Command, and saw action in Europe, the Mediterranean, the Pacific and South East Asia.