The Exxon Valdez tanker that was involved in a huge oil spill off Alaska in 1989 has been banned from entering India where it was due to be dismantled, state officials said Wednesday.

The Gujarat Maritime Board said it had refused permission for the ship, now renamed the Oriental Nicety, to berth in the state after the Supreme Court in New Delhi asked for reassurances over pollution fears.

"Permission has not been given," a board official in Ahmedabad, Gujarat's main city, told AFP on condition of anonymity, adding that the vessel was already in Indian waters.

An Indian ship-breaking company recently purchased the tanker to dismantle it for scrap at the Alang shipyard in Gujarat on the country's west coast.

Environmentalists had petitioned the Supreme Court seeking information on whether the ship had been stripped of all toxic material in line with the United Nations' Basel treaty on hazardous waste management.

"The ship cannot enter any Indian port if it is not in compliance with the UN convention on trans-boundary movement of hazardous waste and their disposal," Gopal Krishna, of the Toxics Watch Alliance, told AFP.

"It is a landmark order from the Supreme Court."

The court directed the government to inform it on "steps being taken to prevent the ship berthing in any of the ports in India, without following the conditions indicated in the Basel Convention."

The Basel Convention, which has been signed by India, governs international movements of hazardous waste and is designed to prevent dumping in the developing world.

The Exxon Valdez spilt around 11 million gallons (40 million litres) of oil into Alaska's Prince William Sound, polluting 1,300 kilometres (800 miles) of coast.

According to the University of Alaska only a quarter of marine wildlife survived the disaster.