Archaeologists hope to shed light on the DNA signature of the Black Death plague after finding what they believe to be a mass grave under central London.

Archaeologists said on Friday they had found a graveyard during excavations for a rail project in London which might hold the remains of some 50,000 people killed by the bubonic plague more than 650 years ago.

Thirteen skeletons laid out in two neat rows were discovered 2.5 metres below the road in the Farringdon area of central London by researchers working on the 16 billion pound ($23 billion) Crossrail project.

Historical records indicated the area, described as a "no man's land", had once housed a hastily established cemetery for victims of the bubonic plague which killed about the third of England's population following its outbreak in 1348.

"At this early stage, the depth of burials, the pottery found with the skeletons and the way the skeletons have been set out, all point towards this being part of the 14th century emergency burial ground," Crossrail's lead archaeologist, Jay Carver, said.

"This is a highly significant discovery and at the moment we are left with many questions that we hope to answer."

The archaeologists hope that the skeletons, which have been taken away for scientific tests, will shed light on the DNA signature of the plague and confirm the burial dates.

They hope the research will help in the fight against modern diseases.

"Many biologists are researching ancient diseases in the hope of better understanding the modern ones," Mr Carver said.

The burial was found during excavations for a rail project in central London. ( Crossrail )

Limited records suggest up to 50,000 victims were buried in less than three years in the Farringdon cemetery as the plague ravaged the capital.

The cemetery find could be the second significant medieval discovery in England recently, after archaeologists confirmed last month they had discovered the remains of King Richard III, who died in battle in 1485, under a car park in central England.

Building works for Crossrail, a new railway link under central London and Europe's largest infrastructure project, have already uncovered skeletons from more than 300 burials at a cemetery near the site of the notorious Bedlam Hospital for the mentally ill in the heart of the city of London.

AFP/Reuters