CANBERRA - Authorities declared parts of Australia's northeast coast a disaster area on Friday after tonnes of oil from a damaged cargo ship contaminated several beaches popular with tourists.

Queensland state Premier Anna Bligh declared Moreton Island, Bribie Island and southern parts of the Sunshine Coast as disaster zones after a ship lost more than 30 tonnes of fuel when its hull was pierced by a container washed overboard.

"It may well be the worst environmental disaster Queensland has ever seen," Bligh told Australian Associated Press. The ship was capable of carrying 100 tonnes of oil and the spill was now much larger than initial reports indicated, she said.

At least 60 kilometres (37 miles) of beach coastline had been covered by the slick, which came from the Hong Kong-flagged ship Pacific Adventurer after it was damaged on Tuesday in heavy seas generated by tropical cyclone Hamish.

A team of environmental cleanup experts was on its way to the area and local people would be barred from the disaster zones to aid a cleanup, Bligh said, ordering an investigation.

"If there is any grounds for prosecution of this ship and its owners, we will not hesitate to take that action. We will also be pursuing them for compensation as this is going to be a very big clean-up cost," Bligh said.

Environment experts said the clean-up would be delicate as cyclonic seas and high tides continued to erode beaches, carrying the spill into nearby rivers. But heavy seas were also helping to break up the slick and push it offshore, they said.

The Sunshine coast is one of Australia's most popular tourist destinations with several major resort towns located not far from the spill area, including the coastal towns of Caloundra, Mooloolaba, Maroochydore and Noosa.

"It's certainly bigger than the first reports I was getting in terms of the extent of it and the magnitude of what's impacting our beaches," Sunshine Coast Council Environment Manager Stephen Skull told state radio.

Environmental Protection Agency spokesman Clive Cook said the spill had already affected small numbers of local wildlife including seabirds and turtles.

Marine experts are also searching for 31 containers of ammonium nitrate, used for making fertiliser and explosives, which were lost from a ship near the city of Brisbane.

If the containers, which have 620 tonnes of ammonium nitrate, leak it could cause major algae blooms which would choke marine life in Moreton Bay, say marine scientists.

(By Rob Taylor, Planet Ark, 16/03/2009)