LONDON — The captain of a cargo ship that collided with a U.S. tanker is a Russian national who remains in U.K. police custody, the vessel’s owner said Wednesday.

The 59-year-old man, who hasn’t been named by authorities, was arrested by police in northeast England Tuesday on suspicion of manslaughter by gross negligence over the collision. He hasn’t been charged.

Shipping company Ernst Russ, which owns the Portugal-flagged cargo vessel Solong, said that the ship’s 14 crew were a mix of Russian and Filipino nationals.

The cargo ship collided Monday with a tanker transporting jet fuel for the U.S. military in the North Sea off eastern England on Monday, setting both vessels ablaze. One sailor from the Solong was presumed dead in the collision, which sparked fears of significant environmental damage.

U.K. authorities say they don’t suspect foul play.