Officials are looking into whether a ship’s anchor may have struck a pipeline on the ocean floor, causing a major leak of crude oil into waters off Southern California.

The head of the company that operates the pipeline said that divers have examined more than 8,000 feet of pipe and are focusing on “one area of significant interest”.

Amplify Energy CEO Martyn Willsher said during a news conference that a ship’s anchor striking the pipeline is “one of the distinct possibilities” for the cause of the leak.

US Coast Guard officials said that cargo ships entering the twin ports of Los Angeles and Long Beach routinely pass through the area.

“We’re looking into if it could have been an anchor from a ship, but that’s in the assessment phase right now,” said Coast Guard Lieutenant Commander Jeannie Shaye of Coast Guard.

The leak reported on Saturday has fouled the sands of famed Huntington Beach and other coastal communities. The spill could keep beaches closed for weeks or months.