India, April 6 -- Swedish authorities have released a tanker sanctioned by the European Union that had been boarded and detained on suspicion of causing an oil spill in the Baltic Sea.

The Swedish Coast Guard said they had not found sufficient evidence that the Flora 1 tanker was at fault for the 12-kilometre-long spill that had been discovered.

Investigators also established that Cameroon had confirmed the vessel was sailing under that country's flag, which had not been clear when the vessel and its 24-member crew were stopped Friday, the coast guard said.

The Flora 1 was put on the EU's list of sanctioned vessels for carrying Russian oil while "practising irregular and high-risk shipping practices." Unsafe practices can include turni...