The court in Goeta, eastern Sweden, upheld an earlier verdict, saying there was no proof that the oil leak from the Figaro, since then re-named Fagervik, in February 2001 was intentional, TT news agency reported.

While there was no doubt that the oil spill, detected from the air by a fighter plane pilot, did indeed come from the Figaro, it could have been caused by a damaged valve, the court said, adding that the jury was split on the question.

Environmental organization Greenpeace reacted angrily to the verdict, saying "the oil could not have leaked by mistake", and calling for tighter environmental rules for vessels in the Baltic.

Last June, Swedish police arrested four Greenpeace activists trying to blockade the Figaro in the port of Norrkoeping as part of the organization's campaign against oil spills in the Baltic.

At the time, a number of Swedish businesses said they would use other vessels to transport their cargo in future.

According to Greenpeace, between 1,000 and 2,000 cases of illegal emptying of oil tanks occur every year in the Baltic.

SPACE.WIRE