Transport Minister Ahmed Ali said the inquiry would investigate whether navigational error was responsible for the Greek-controlled Tasman Spirit's grounding on July 27.

"The inquiry committee will look into the human error aspect of the incident but we can't comment further because of legal bearings involved in the matter," he told reporters.

He played down the possibility that the 24-year-old vessel may have deliberately run aground.

"Insurance companies are not fools and they could not be defrauded in such a childish way," Ahmed told AFP.

"The inquiry committee may not even not make this part of their terms of reference."

The ministry's new director general of shipping and ports, Anwar Shah, has been appointed to head the inquiry committee.

The Tasman Spirit has leaked up to 15,000 tonnes of oil since drifting into a shallow channel off Karachi's busy commercial port and splitting in two last week.

"I can conservatively say that 12,000 to 15,000 tonnes of oil have been spilled from the ship," Ali said.

Shah said he would interrogate the ship's captain and other members of the crew, which included five Greek nationals and several Filipinos.

"Talking to crew members and having their version will be a part of our enquiry," he told AFP, adding that the captain was still in Pakistan although some crew members had already left.

The tanker was carrying 67,000 tonnnes of crude oil bound for the state-run Pakistan Refinery when it ran aground.

The vessel is managed by Greek company Polembros Shipping, headed by well-known Greek shipping magnates from the Polemis family.

The company is based in Greece's main port of Piraeus, according to Polembros spokesman David Gare.

Gare, who said the ship's listed owner Assimina Maritime was also registered in Piraeus, blamed the grounding on human error.

"It's an unfortunate case of poor navigation," he told AFP in Athens.

"The best evidence to bolster (this claim) is the fact that Pakistani authorities suspended the pilot."

A press release last week from Assimina Maritime stated: "From independent investigations to date the cause can be attributed to human error. The pilot was suspended pending a formal inquiry by the Karachi port trust."

The vessel's owners were shouldering the cost of the clean-up exercise, Gare added.

Pakistan has demanded compensation for damage and clean-up costs, filing an initial claim with the International Maritime Organisation for 200,000 dollars, Ali said.

Maritime authorities called the spill Pakistan's worst-ever port disaster.

"It was the worst-ever oil spillage on the Karachi shore in last 30 years. There has never been such a big accident at the port," the transport ministry's director of shipping Saleem Baloch told AFP.

The provincial Environment Protection Agency concurred.

"This was certainly the worst-ever ecological disaster on our shores," the agency's deputy director Irfanullah Tonio told AFP.

The International Tanker Owners Pollution Federation said the salvage operation had failed to plug an ongoing "light" spillage.

Some 20,000 tonnes had already been salvaged from the ship before it broke up on August 14. Efforts since Sunday have retrieved another 12,000 tonnes, Ali said.

"But bad weather is...forcing us to stop it," he said.

The spillage has destroyed young mangroves, turtles and fish along Karachi's 16-kilometer (10-mile) coastline.

TERRA.WIRE