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.

British police said Friday the Russian captain of a cargo ship that collided with a U.S. tanker has been charged over the death of a crew member, who is missing and presumed dead. Vladimir Motin, who was the master of the Portugal-flagged cargo vessel Solong,

Motin was the master of the Ernst Russ-operated 804-teu Solong (built 2005) that collided with a Stena Bulk tanker on Monday off the northeast English coast. UK prosecutors named the seafarer who died in the collision as Mark Angelo Pernia, a Filipino crew member on the Portuguese-flagged Solong.