As oil continues to spew into the Gulf of Mexico, there are fears about the potential for another smaller spill in Papua New Guinea.

Two big oil tanks are leaking heavy fuel oil close to the sea on the island of Bougainville.

The tanks used to fuel the massive Panguna copper mine before it was abandoned more than 20 years ago because of a bloody civil war.

The mine's Australian owner says it wants to clean up the leaks, but Bougainville is still too dangerous for its workers to return.

It has been more than 20 years since the two large fuel tanks at the port of Loloho on Bougainville's east coast had any maintenance.

Back then, the resentment local landowners felt towards the Panguna copper mine sparked a decade long-civil war that forced the mine's closure.

Now the tanks are leaking and the ground around them is coated in thick heavy fuel oil.

A black lake lies between the tanks and there are fears it could get worse.

"There's a faint crack down through there," said Ron Blenkiron from South Pacific Environmental, a company that wants to clean up the leak.

"This is about 20 mil thick at the bottom here but these cracks will still open up in an earthquake or anything serious like that, so it's definitely an issue."

The tanks are only a stone's throw from the ocean and Mr Blenkiron says the system put in place to contain leaks has broken down.

An oil-soaked pit, just metres from the water, is the last barrier preventing the fuel from leaking into the sea.

"During the wet season, when we first came here, this pit was basically full of water and the oil was about 50 mils from running into the sea, so it was pretty close," Mr Blenkiron said.

"You're living on the edge of a catastrophe here."

More mess

Mr Blenkiron says the oil is not the only potential hazard left behind when the mine was abandoned in the late 1980s.

A few hundred metres up the road are the rusting remains of a storage area for chemicals used in the mining process.

Mr Blenkiron has written to the mine's Australian owner, Bougainville Copper Limited (BCL), and offered to clean up the area for a price.

But BCL has declined.

"I believe that BCL is morally responsible to clean up," Mr Blenkiron said.

"I mean, sure they may have got chased out of here rightly or wrongly a number of years ago but there's no danger in coming down here. The people are welcoming. They're easy to work with."

BCL's chairman Peter Taylor, based in Port Moresby, does not believe the leaking tanks pose a danger to the environment.

"There's no disaster there," he said.

"There is what I call a relatively minor oil spill that's been contained by the safety systems that were put in place. And really it seems to me it's just a case of going in and cleaning that up."

Mr Taylor says vandals caused the leaks and most of the oil has already been stolen.

He rejects the claim there is other toxic chemicals in the area, saying New Zealand peacekeepers assessed the port in 1997 and removed anything dangerous.

Dangerous region

Mr Taylor says BCL wants to clean up the spill, but more than a decade after the civil war ended, he believes Bougainville is still not safe for his employees.

"Unfortunately there are a few people, and I think they're now well and truly in the minority who refuse to allow us access and some of these people unfortunately have got guns," Mr Taylor said.

There is no doubt law and order is still a problem in Bougainville.

Twice this year foreign ships have docked at Loloho without customs clearance and pumped oil out of the tanks, without approval from BCL.

There are also plenty of guns on the island that are yet to be disposed of in line with the Bougainville Peace Agreement that ended the civil war.

So why doesn't BCL use South Pacific Environmental, who are already on the ground, to clean up the leak?

"We've done some research to try and find out what their credentials are and as far as I can see they have no experience in actually doing any sort of environmental remediation work," Mr Taylor said.

Mr Taylor is hopeful BCL will be able to return to the island soon, not only to clean up but also to resume mining.

"The landowners are now approaching the company and saying 'we'd like you to come back, we'd like you to do various things including the remediation of anything that might be in any way dangerous'," he said.