The Russian captain of a cargo ship that collided with a U.S. tanker earlier this week appeared in a U.K. court Saturday where he was remanded in custody over the death of a crew member, who is missing and presumed dead.

A port official said he was told the North Sea collision produced "a massive fireball" and the cargo ship's owner said one crew member was missing.

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.