Sunken German U-boat found

Footage of the U-166 on the floor of the Gulf of Mexico

Two international oil companies say they have discovered the location of a sunken wartime German submarine in the Gulf of Mexico close to the United States coast.

The oil companies, BP Amoco and Shell, stumbled across the wreckage of the U-boat while surveying for a planned underwater oil pipeline, about 70 km (45 miles) from the mouth of the Mississippi River.

The SS Robert E Lee was heading for New Orleans when it was sunk

It was found near the wreckage of an American freighter, the SS Robert E Lee, which it torpedoed on 30 July 1942.

The freighter had been heading for the southern US city of New Orleans, and was carrying 400 passengers and crew.

Twenty-five of the people on board died.

War grave

Salvage workers have been trying to locate the U-166 ever since it was sunk by the US military a short time later.

All 52 crewmembers on board the submarine were killed.

It is believed to be the only German submarine to have been sunk in the Gulf of Mexico.

"Both the Robert E Lee and the U166 are protected by International Treaty," Hugh Depland, Public Affairs Manager for BP, told ABC News.

"They are war gravesites; they cannot be disturbed in any fashion, they can't be dived upon, they can't be recovered and we would make no attempt to do that," he said.