However, it was not just piracy for which Kidd was executed, but also for the murder of a member of his own crew. In 1697, he killed a mutinous gunner, William Moore, by hitting him over the head with a bucket, fracturing his skull. But Hamilton and Macort's latest research suggests that under Admiralty law – under which Kidd might have been, at worst, scolded for attempting to suppress a mutiny in such a violent manner – he should have been exonerated of that charge.

"The newest development is our examination of the key difference between civil and Admiralty law in the early 18th century," says Hamilton. "Our research reveals that if Kidd had been tried under Admiralty law, in a maritime court where virtually all other pirates were tried, he would probably have been exonerated on the charge of murder and perhaps even the charge of piracy.

"When Kidd threw a bucket at his gunner, he was within the rights granted to British navy captains, especially because Moore was stirring up a mutiny. But under civil law, the fatal blow helped cost him his life."

Over the years, many historians have argued that Kidd was simply a scapegoat, that he was used by some of the most powerful men in England to advance their wealth, then abandoned by those very men when the scheme imploded.

"What this was really about was some very powerful lords who had been frozen out of the English East India Company hiring a captain to chase pirates and bring back the wealth of the Indies – even if some of that wealth happened to be recently stolen from the English East India Company and some other very wealthy Englishmen," says Richard Zacks, author of The Pirate Hunter: The True Story of Captain Kidd.

"Kidd's mission was to bring stolen goods back to New York and then divvy up the profits. The origins of the items were not very important to the lords until the whole scheme blew up when Kidd was accused of piracy."

The captain of the Quedagh Merchant may have been an Englishman, but he had purchased passes from the French East India Company, promising him the protection of the French Crown. These passes, which may have saved Kidd from the hangman's noose, were suppressed at his trial and were not to surface again for more than a century.

- The Scottsman,10 July 2009, Alice Wyllie

Scottish Parlimantary Motion S3M-4427: Bill Kidd: Vindication of Captain William Kidd— That the (Scottish) Parliament welcomes a fresh bid to clear the name of Captain William Kidd, a legendary Scottish seafarer and privateer who was hanged for piracy in 1701, following new evidence from the United States of America that is under consideration by the Fraternity of Masters and Seamen in Dundee and contests the charge of piracy that condemned Captain Kidd to the gallows over three centuries ago.