In a statement, ErnstRuss, the Hamburg-based owner of MV Solong, said the captain was Russian, and added that the rest of the crew were a mix of Russian and Filipino nationals.
Jerome Mayhew, the shadow transport minister, said the nationality of the Solong’s captain raised “further questions” about the incident.
He told PA news agency: “Where military assets are damaged it is vital that motives are fully investigated to exclude foul play. The nationality of the captain of the Solong raises further questions about potential motivation that the Government must now get to the bottom of.”
The US military chartered tanker MV Stena Immaculate was hit by the MV Solong container vessel on March 10. Photo / AFP
A Government source declined to comment, and said the investigation into the container ship’s master was now a police matter.
Mike Kane, the Transport Minister, told MPs on Monday that while something went “terribly wrong” when the MV Solong cargo vessel crashed into the tanker that was carrying some 220,000 barrels of jet fuel, there was no evidence to suggest foul play “at the moment”.
On Tuesday, Humberside Police said a 59-year-old man had been arrested on suspicion of gross negligence manslaughter in connection with the collision.
Following the collision both vessels caught fire. It was later revealed the US military-chartered Stena Immaculate was carrying jet fuel. Photo / Getty Images
In a statement on Wednesday morning, the force said that “a 59-year-old man remains in our custody” and detectives were “continuing to conduct extensive lines of inquiry”.
A crewman who remains unaccounted for is now presumed dead after going missing during the collision.
Data from the ship-tracking website Marine Traffic suggests the Solong was travelling at 16 knots (29km/h) at the point of impact.
Large explosions followed, as both vessels became engulfed in flames, forcing the crews to abandon ship.
One surviving sailor said crewmates had their hair singed, before managing to get aboard a lifeboat.
The two ships were originally locked together after impact but became unattached on Monday evening, causing the Solong to start drifting south.
By Tuesday evening, the HM Coastguard said the fire onboard the Stena Immaculate was “greatly reduced with no flames visible”, although the Solong remained alight.
The cargo ship is still drifting and on fire in the North Sea, but is not expected to sink.
The collision and subsequent pollution spill have sparked fears it could be the largest environmental disaster in the UK for a generation.
The MV Solong had recently failed steering-related safety checks.
Port state control inspection documents from July last year show Irish officials deemed Solong’s “emergency steering position communications/compass reading” was “not readable”.
This was among 10 deficiencies highlighted during the inspection of the Portuguese vessel in Dublin.
Other issues included alarms being “inadequate”, survival craft “not properly maintained”, and fire doors “not as required”.
