Police in Britain on Tuesday arrested the captain of a cargo vessel that crashed into a tanker in the North Sea on suspicion of gross negligence manslaughter.

The incident happened on Monday when the Portuguese-flagged ship, the Solong, collided with the anchored US tanker Stena Immaculate off the east coast of Yorkshire.

The tanker, which the US military had chartered, was carrying jet fuel.

The collision triggered a huge inferno and left one crew member missing, who has since been presumed dead.

Criminal investigation launched

The 59-year-old captain was arrested by Humberside police in northeast England.

Shipping firm Ernst Russ issued a statement saying that it "can confirm that the master of the... Solong has been detained" in the UK.

"The master and our entire team are actively assisting with the investigations," it added.

Humberside Police said it had launched a criminal probe, along with the Maritime and Coastguard Agency, into what caused the crash.

Environmental impact remains under assessment

The UKcoastguard said it had attached a tow line to the Solong and it was offshore "in a safer position."

An initial assessment had said that the ship was unlikely to stay afloat but transport minister Heidi Alexander said on Tuesday that neither boat will sink.

The Stena Immaculate remains at anchor with safety tug boats, the coastguard said, adding that it has a "greatly reduced" fire with no visible flames.

Crowley, the maritime company managing the Stena Immaculate, said it remains unclear how much Jet A1 fuel was released when it was hit by the Solong, but an initial review shows it had evaporated due to exposure to fires on both vessels.

Authorities are ready to deploy equipment to minimise pollution at sea, including spray dispersants for oil spills and containment booms, if required, the British government said.

The coastguard said a one-kilometre (0.62 mile) exclusion zone had been placed around both vessels.

Edited by: Louis Oelofse