Although historians at the British Museum were initially deeply sceptical of the claim, hundreds of pieces of gold found on the seabed will go on display at the museum next week with a label acknowledging the possibility that the wreck off Salcombe could have been a pirate ship, and even a Barbary corsair.

The amateur divers who found the ship are convinced that research on the wreck is uncovering a largely forgotten history of human misery.

The idea of white slavery, overshadowed by the unarguable brutality of centuries of the trade in black slaves, is now mainly dismissed as the stuff of Victorian novels, while the "Barbary corsairs" became pantomime figures. The terror of the pirate raids remains a vivid folk memory on Mediterranean islands, but it has largely been forgotten that they also raided as far north as the coast of Scotland, in search not of ships or gold but human booty.

However, academics are re-examining the subject, with startling results. Linda Colley's recent book, Captives, draws together hundreds of accounts of capture by pirates, and the desperate pleas to parliament for help from those left behind.

The divers' claims for the Salcombe wreck are backed by another academic, Robert Davis of the University of Ohio, who is also completing a study of the white slave trade. He believes that in the 250 years from 1580 more than a million Europeans were kidnapped for slavery or ransom.

The wreck was located six years ago by Neville Oldham, a former Grenadier Guard and retired builder, and his friend, Ron Howell. The ship had broken up almost without trace -only one chunk of oak has been recovered despite meticulous seabed surveys, but a wealth of contents has been raised, including cannons, personal possessions such as Dutch porcelain and pipes, and the largest haul of 17th century Islamic gold ever found in British waters.

Both men, who have formed a local group of amateur underwater archaeologists, are convinced the ship was a xebec, the fast, light, triangular-sailed craft, rowed by slave crews, used by the Barbary pirates. The scatter of cannon is unusual, suggesting that they were mounted only at the fore and aft of the ship, leaving space clear for the oars. They believe the reason no other timbers have been recovered is because the light shallow hulled ship would have turned turtle and been broken up on the rocks, rather than sinking in one piece like the heavy European ships.

The story of the shipwreck has been taken up by documentary film makers, and will be seen on BBC 2 next Friday. The film crew commissioned tests on the one piece of timber recovered, which suggest a north African origin.

Mr Oldham said he suspected a pirate connection as soon as he realised that all the beautiful gold coins and jewellery they had found were chopped in half - in order, he believes, to divide the spoil between the pirates.

The gold will go on display at the British Museum from January 14. The museum historians describe it as: "A unique find in the history of Britain. It provides us with tangible evidence of a flourishing trade taking place between Morocco and Europe from the late 16th century. The fragmentary condition of the gold jewellery and ingots suggests that this may have been a hoard of bullion, exported with the intent of melting it down. The identity of the ship is not known: it may have been an English or Dutch vessel, or a ship of the Barbary pirates."

They will go no further on the nature of the "flourishing trade", but Mr Oldham is convinced he knows the truth.

"The fact that people have forgotten about this doesn't mean it never happened," he said. "History is written by rich people. When the rich were captured they were ransomed. When the poor were taken they disappeared without anyone recording their names."

· White Slaves, Pirate Gold - Timewatch, 9pm Friday January 10, BBC 2