Kaliningrad deputy governor Vladimir Pirogov said that beaches on the Baltic enclave had been "promptly cleaned of oil," including the Curonian Spit, an extended sand dune almost 100 kilometres (60 miles) long that is shared by Russia and Lithuania and on the UNESCO world heritage list.

"Experts have taken several samplings of sea water but have found no oil products in them," Pirogov said, as quoted by the Interfax news agency.

Russian servicemen, muncipal workers and schoolchildren helped to clear some 20 kilometres of coastline and there is no longer any reason to consider emergency measures, he said.

On Tuesday a local emergencies ministry official said that more than 300 kilogrammes (650 pounds) of oil had polluted the coast, and described the situation in the Curonian Spit, a natural reserve, as "critical."

But Pirogov said that water samplings indicated the oil products had been in the sea for a long time before being thrown onto the shore.

However local ecology activists gave a different picture, a spokesman for the local Ecodefence group saying they believed 200 kilometres of coastline had been poluted by oil spills totalling some 40 tonnes.

Alexandra Korolyova noted that local experts had been unable to determine precisely the type of oil that had been spilled and were continuing to demand emergency measures for the region, Interfax said.

Officials said Tuesday the oil spills could have been caused by the sinking last May of a Chinese cargo ship, the Fu Shan Hai, which was carrying 66,000 tonnes of fertilizer and 1,600 tonnes of heavy fuel when it collided with a Cypriot container ship near the Danish island of Bornholm.

Ecodefence however dismissed the hypothesis "an invention," claiming that the pollution was caused by an offshore oil rig belonging to the Russian oil firm LUKoil.

The Curonian Spit, whose width varies between 400 metres and four kilometres with dunes up to 100 metres high, has seen human habitation since prehistoric times.

It is constantly subject to erosion by the natural forces of wind and water, and has survived to the present day only as a result of human intervention.

TERRA.WIRE