Riyadh  - Somali pirates have released the Sirius Star tanker seized off the Kenyan coast in mid-November, an official at the Saudi Oil Ministry confirmed Friday.

The supertanker carrying 100 million dollars-worth of crude oil was seized some 830 kilometres off the Kenyan coastal city of Mombasa.

A Saudi ministry spokesman made no mention of any ransom having been paid. Media reports had said the pirates had demanded between 2 million and 25 million dollars for the return of the supertanker.

The 330-metre-long vessel was carrying oil for Vela International Marine Limited, a subsidiary of the Saudi Arabian state-run Saudi Aramco firm to the United States. It can carry up to 2 million barrels of oil.

When the pirates seized the Sirius Star and its 25 crew members, it was the largest vessel taken by pirates and represented their most daring raid to date, despite the presence of international warships.

The ship's crew, who were from Britain, Croatia, the Philippines, Poland and Saudi Arabia, were said to be safe during their abduction, Vela International said in a statement on its website at the time.

In 2008, pirates attacked over 100 ships off the Somali coast and seized around 40 vessels. They demanded millions of dollars in ransom.

Foreign navies have sent over a dozen warships to the area seeking to stop piracy in the region, which has driven up shipping costs and forced some ships to re-route around Africa rather than passing through the Suez Canal.

In December, the European Union launched its Atalanta anti-piracy mission in the Gulf of Aden, a relatively narrow and busy shipping channel which forms part of the route linking the Indian Ocean with the Mediterranean Sea through the Suez Canal.

Operation Atalanta comprises three warships, a logistics vessel and three reconnaissance planes.

In November, an Indian navy stealth frigate, the INS Tabar, staved off attacks on merchant vessels from India and Saudi Arabia and returned fire on a pirate vessel that threatened it. (dpa)