The embarrassment caused after a British warship ran aground on well-charted rocks was further compounded yesterday following reports that it had caused an oil slick.

The embarrassment caused after a British warship ran aground on well-charted rocks was further compounded yesterday following reports that it had caused an oil slick.

As speculation mounted that HMS Nottingham's captain, Commander Richard Farrington could face a court martial, he blamed "human error" and unfortunate circumstances" for the incident.

"We have done significant damage to a major British warship," he conceded yesterday, adding: "This is not a good day for me."

He continued: "This is quite the worst thing that has ever happened, quite the worst. Character-building stuff."

The 41-year- old officer appeared to accept that he would have to face disciplinary action for the holing of the £300m warship. "You run the ship aground, you get court martialled," he said.

Divers were assessing the extent of the environmental damage caused by the destroyer yesterday. As the divers were going about their work, the Royal Navy launched an internal inquiry into the accident.

Ministry of Defence officials played down reports that a half-mile oil slick had formed around the stricken 3,500-ton ship, now anchored in a sheltered harbour, insisting a slight "sheen" of oil on the surface was not a cause for concern.

A spokeswoman said: "No significant damage to the environment has been found at the moment." She also denied claims by anti-nuclear protesters that the ships was escorting a consignment of nuclear fuel.

She said the ship was damaged on Sunday in bad weather while it was on a routine trip from Queensland to New Zealand . It struck rocks near Lord Howe Island.

The ship is believed to have collided with the well-charted Wolf Rock as it manoeuvred to get one of its Lynx helicopters into its hangar during the shore transfer of a sick crew member.

Cdr Farrington said he had ordered both gas turbines full speed astern, putting the ship into reverse, as soon as he realised what had happened.

He had considered grounding the destroyer on the rock to stop it from sinking but said HMS Nottingham would "break its back" if left on the reef, forcing her crew to abandon ship in dangerous weather.

Crew members, he said, worked through chest-deep water to shore up watertight bulkheads. Five internal compartments, including crew sleeping quarters, flooded.

"They were bloody magnificent," said Cdr Farrington. "They saved the ship last night."

The 253 crew were uninjured but Cdr Farrington, who has been Nottingham's captain for 18 months, said he had feared the worst because she was being pounded by heavy seas. "It endangered the lives of 250 men and women," he said.

Commander David Heley, spokesman for the MoD, came to his colleague's defence yesterday, praising him as a "cool, phlegmatic individual", adding "[ Nottingham] is a warship designed to take a fair degree of action damage".

The destroyer is at anchor while a decision is reached on whether it can get to a port under its own power or if it must be towed. The bad news for Cdr Farringdon is that at least three Royal Navy commanders have been court martialled for running ships aground in the past 10 years.