Image caption It is thought that only up to 50 Spitfires are airworthy today

British experts have begun work in Burma following a 17-year search for a cache of World War II Spitfire planes believed to be buried in the country.

Eyewitness accounts and metallurgical surveys suggest that more than 30 unused planes are buried in crates at Rangoon international airport.

The planes are believed to have been buried by American engineers as the war drew to a close.

Only an estimated 40 to 50 Spitfires are believed to be airworthy today.

The planes at the airport site are thought to be among more than 120 unassembled Spitfires buried at at least three different sites in Burma.

The team behind the historical treasure-hunt believe that the planes may still be in good condition if packed carefully.

"It's taken me 17 years to find these aeroplanes in Myanmar [Burma] and we're pretty sure we know the location," said British aircraft enthusiast David Cundall, who led the search.

It took Mr Cundall close to a decade to sign an actual contract to start digging for the planes. The project is being funded by a videogame company in Belarus.

The search team includes archaeologists, film crew and survey experts. An initial survey is expected to take 10 days, and then excavations could take between four and six weeks.