Antananarivo: The producer leading a television documentary team that says it has found 17th-century pirate William Kidd`s sunken ship fought back on Wednesday against a UNESCO report dismissing their claims.
Sam Brown, who is making a film with marine archaeologist Barry Clifford, called UNESCO`s report a "disgrace" and said the UN body was motivated by its opposition to privately-funded research.
"UNESCO will attempt to discredit Barry Clifford by whatever means they can," Brown said in an email to AFP.
"They have exhibited a frankly shocking lack of transparency and impartiality throughout.
"They dived on the wreck site for less than four days in poor visibility and used very questionable methods."
Clifford declared in May that he had located the wreck of Kidd`s legendary "Adventure Galley" ship -- and a 50-kilogramme (110-pound) silver ingot of plunder -- off the coast of Madagascar.
UNESCO, the UN`s scientific and educational arm, flew experts to the site in the Indian Ocean to investigate the claims, and issued its damning report on Tuesday.
It said the "silver" ingot was just a lead weight, and that the supposed shipwreck was rubble from old port construction.
Brown, who is making the documentary for the History Channel, said Clifford`s team had investigated the site in a bay of Sainte Marie, a small island east of Madagascar, for 15 years.
"Maps and primary source documents clearly state that Captain Kidd scuttled his ship in this area," he said.
"The extensive geophysical survey... identified 13 shipwrecks in total, but only this one fits the profile of the Adventure Galley."Brown expressed surprise that the ingot was made of lead as Clifford was "100 percent convinced it was silver".
"I do not believe the UNESCO team were even diving on the correct shipwreck," he added.
The notorious Captain Kidd, who was born in Scotland in about 1645, was first employed by British authorities to hunt pirates, before he himself turned into a ruthless criminal of the high seas.
The fate of much of his booty has remained a mystery, sparking intrigue and excitement for generations of treasure-hunters.
Clifford garnered world headlines in May when he unveiled the "silver ingot" -- supposedly part of Kidd`s ill-gotten gains -- at an event attended by Madagascan President Hery Rajaonarimampianina and the US and British ambassadors.
But Michel L`Hour, head of the UNESCO team, was less impressed.
"How can anyone just get out of the water and say, `I`ve found Captain Kidd`s treasure`?" he told AFP.
This is the second time UNESCO has clashed with Clifford.
Last year, he claimed he had identified the wreck of Christopher Columbus`s flagship that sank in 1492 off the northern coast of Haiti.
The claim was soon disproved by UNESCO, which determined it was a ship from a later period.
Clifford is best known as the discoverer and excavator of the world`s first fully verified pirate shipwreck, the Whydah, in 1984.