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.

The captain of a cargo ship that collided with a U.S. tanker is a Russian national who remains in U.K. police custody.

Extra time is "imperative to the investigation" because of the "complexities of the incident" and the "number of witnesses involved", Humberside Police says.