The small navy vessels have been there for more than six decades, and Phuket Governor Udomsak Asavarangura insists they will stay there, having discussed their future with the British Navy.

Udomsak said he had received a letter from the British ambassador asking the province to suppress any operations by East Marine SBS, who in April requested permission to salvage the "torpedoes", or Chariots, as they were known, which are believed to belong to Britain's Royal Navy.

Chariots, secret naval weapons commissioned during World War II, were electrically propelled mini-submarines that carried two crewmen, who sat astride the vessel. They steered it at slow speed towards an enemy ship, attached a mine to the ship, then rode the "torpedo" away. The Chariot was carried by another vessel, generally a manned submarine, and launched near the target.

Udomsak said the letter suggested the British Navy had no intention of allowing the private company to do anything with the sunken vessels.

He said the navy was concerned the "human torpedoes" might be damaged during the salvage process, transportation or when they were inevitably put on display.

"It prefers scuba divers to see the vessels on the sea floor," the governor said.

The letter also said that according to international law, sunken warships remain the property of the owner government.

The governor said the British government had the authority to stop their salvage.

"We also consulted with military diplomats, who said traditionally the British government did not recover sunken warships," Udomsak said.

These particular Chariots were sunk in action near Dok Mai Island. Records suggest the British submarine Trenchant carried two Mk-2 Chariots for a mission in Phuket harbour on October 27 and 28, 1944.

Udomsak said Phuket planned to develop the area where the two vessels are lying as a recreational dive spot.