The captain of the Solong cargo ship who was arrested after crashing into an oil tanker off the English coast is a Russian national, the vessel’s owner said Wednesday, as maritime experts search for answers.

Fears of an environmental disaster eased on Wednesday, two days after a container ship ploughed into a stationary U.S. fuel tanker off northeast England, as the vessel's owner said the detained captain was a Russian national.

U.K. police say the Solong cargo ship's captain, identified by the vessel's owner as a Russian national, was detained on suspicion of negligent manslaughter.