Greenpeace says fuel oil possibly from a sunken Russian fishing boat has washed up on the southern coast of one of the Spain's Canary Islands.

The environmental group said Thursday the fuel reached Veneguera beach on Gran Canaria island, a top European vacation spot.

The Development Ministry said Wednesday a 4-kilometer (2.5-mile) long slick was spotted off Veneguera but it was not certain if it came from the boat. It said vessels were trying to clear it.

The Russian trawler Oleg Naydenov, carrying 1,400 metric tons of fuel oil, caught fire in a Canary Island port April 11 and was towed out to sea and sank April 14 about 24 kilometers (15 miles) south of the island.

The ministry said a submersible has begun dives to examine the vessel.