London, Aug 27 (IANS) Scientists claim to have solved the mystery of the disappearing oil from the BP spill in the Gulf of Mexico.

They believe that billions of oil-eating bugs have already done the most challenging part of BP's clean-up job.

The bacteria, called oceanospirillales, munched through massive oil plumes in the Gulf of Mexico following the world's worst-ever spill, reports the Daily Mail.

It was caused by nearly five million barrels of oil gushing into the ocean over 87 days before it was capped.

The experts examined a 35-km, 3,600-foot-deep plume in May and June and found a growing population of carbon-eating bacteria about 10 km from the leak.

The bacteria worked so fast that each time the scientists could get back to the lab to test seawater samples, the bugs had already eaten all the oil in them.

Earlier this month, when the team returned to where the plumes had been, the bugs were still there but the oil was gone.

Terry Hazen, head of Lawrence Berkeley National Lab's ecology department in the US, said DNA tests showed that the bugs had genes for processing oil.

'We've never seen anything that can do better than the bugs,' he said.

However, another expert claimed that the plumes may have diluted or moved.