The captain of the Solong - the container ship involved in the crash in the North Sea - is a Russian national, the vessel's owners has said.
The rest of the crew were Russian and Filipino nationals, according to shipping company Ernst Russ.
It comes after police said a man had been arrested on suspicion of gross negligence manslaughter in connection with Monday's collision.
Humberside Police said a 59-year-old is in custody to allow enquiries to take place, and officers are talking to those involved to find out what happened.
The force added investigators have started a criminal probe into the cause of the collision between the Stena Immaculate and Solong off the coast of East Yorkshire on Monday, and are working with the Maritime and Coastguard Agency.
One person remains missing and is presumed dead.
The Stena Immaculate was carrying jet fuel and had been chartered by the US military at the time of the collision.
Ship tracking software showed the Stena Immaculate was stationary as the Solong sailed towards and into it.
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