A Japanese salvage ship was expected to arrive later on Wednesday to help determine the exact location and condition of the 998-tonne Solar 1 under about 640 metres (2,100 feet) of water, Coast Guard chief Arthur Gosingan said.

The 15,000 inmates at a maximum security prison in southern Manila, including 1,000 on death row, began donating hair on Tuesday as health officials ordered the evacuation of residents of a fishing village on Guimaras due to health risks.

"We're collecting plenty of hair to send to Guimaras to solve the oil spill problem," Vergilio Santos, 42, who is serving a murder sentence at New Bilibid Prison, told Reuters television after his head was shaved by a barber.

"This is a contribution even though it's a small part," said Nigel Richard Gatward, a 37-year-old British national convicted of drug smuggling.

The Coast Guard plans to put chicken feathers and human hair in sacks tied to bamboo poles as barriers along the coastlines of affected villages on Guimaras and in nearby Iloilo province.

Residents have been using rice straw in sacks to contain the oil slick, which has affected 46 villages on Guimaras and in Iloilo, as well as a marine reserve.

EVACUATION

More than 40,000 people and 200 km (120 miles) of coastline have been affected by the spill from the tanker, which was chartered by Petron Corp., the country's largest oil refiner.

Health officials recommended the evacuation of residents living near the shore in Lapaz village on Guimaras after monitoring showed an increase in air pollution in the area.

Some 96 families were asked to leave Lapaz on Wednesday, said village head Veronica Ortiz, adding that 24 families fled on Tuesday to stay with relatives elsewhere or in schools converted to temporary shelters in other parts of Guimaras.

"I can no longer stand the stench. It's making me cough," Emiliano Penaflor, 81, said as he gathered a few belongings.

Soldiers, who set up checkpoints in Lapaz, asked journalists to wear masks before entering the village.

"Our tests showed high levels of hydrogen sulfide, benzene and toluene," Health Secretary Francisco Duque said. "Prolonged exposure to these can create health hazards to residents."

Contaminated water could cause skin irritation, he added.

At least a 10th of the tanker's cargo of 2 million litres of bunker oil initially gushed out, polluting beaches and the marine park with black sludge, but there have also been signs of fresh leaks from the sunken ship.

The Maritime Industry Authority, a state agency, has stopped the owner of the sunken tanker from operating two other vessels hauling bunker fuel pending a "thorough inspection".

Vicente Suazo, the agency's administrator, said he also ordered inspections of oil tankers operated by all companies to prevent similar incidents in the future.