NManila - A three-member UN team has arrived in the Philippines to assess the environmental threat posed by a sunken ferry carrying toxic chemicals and bunker fuel, a transport official said Saturday.

The MV Princess of the Stars sank off Sibuyan Island, 300 kilometres south of Manila, on June 21 with more than 800 people on board. Only 56 people survived the accident, while more than 200 bodies have been recovered.

The vessel was carrying large shipments of chemicals, including endosulfan, a highly toxic pesticide.

Transportation Undersecretary Elena Bautista said the UN team will spend a week in Sibuyan to determine if there is a need to dispatch a bigger group of specialists to salvage the cargo of endosulfan.

"They will be there to make an assessment and join up with the team from the (Philippine) Bureau of Fisheries and Aquatic Resources that has established a laboratory on site so that they can more regularly test the water samples," she said.

Bautista said she will meet with the UN team, composed of a marine chemist, an eco-toxicologist and a civil protection expert, on Monday.

The experts arrived in the Philippines on Friday amid concerns that the cargoes of endosulfan, other pesticides, and 10,000 litres of bunker fuel could cause an ecological disaster.

The government earlier announced that the sunken ferry would be refloated to retrieve the toxic chemicals and hundreds of bodies trapped in the wreckage.

But officials said the process could take up to three months.

The sinking is one of the worst maritime disasters in the Philippines. In 1987, the MV Dona Paz collided with an oil tanker just before Christmas, killing 4.341 people in the world's worst peacetime shipping disaster. (dpa)