Police have detained the master of the container ship Solong as experts voiced growing fears over the environmental impact of the collision in the North Sea.

The 59-year-old was arrested on suspicion of gross negligence manslaughter after the search was called off for a sailor onboard the Solong, which drifted ablaze off the coast of Yorkshire on Tuesday.

The ship’s owner, the Hamburg-based maritime firm Ernst Russ, confirmed to the Guardian that the ship’s master had been detained by Humberside police, adding: “The master and our entire team are actively assisting with the investigations. Out of respect for the investigation and all involved we will not comment further at this time.”

The investigation into the cause of the collision had been led by experts at the Marine Accident Investigation Branch but was escalated to a criminal investigation after early inquiries by Humberside police.

The Stena Immaculate was carrying 220,000 barrels of jet fuel for the US air force when it was struck while stationary by the German-owned Solong on Monday morning. At least one of its tanks is leaking into the North Sea.

The transport minister Mike Kane said there was “no evidence” of foul play at present but that something had clearly gone “terribly wrong”.

The burning wreckage of the Solong could be seen drifting southwards off the coast of Grimsby on Tuesday. The smoking vessel was being shadowed by two tugboats to ensure it stayed away from land as it passed a nature reserve off the Humberside coast.

The ship is now expected to stay afloat, the transport secretary, Heidi Alexander, said.

“I am reassured to hear indications from the ship’s owners which suggest the sodium cyanide containers were empty and that efforts to confirm this by the salvors are under way,” she said in a statement on Tuesday.

“I was also pleased to have been informed that early indications suggest that both vessels are now expected to stay afloat and that the Solong can be towed away from the shore, and salvage operations can get under way.

“I will continue to monitor the response and have asked for regular updates, including on any potential environmental impacts, across government and our agencies.”

Mike Ross, the Lib Dem leader of Hull city council, called on Keir Starmer to convene an emergency Cobra meeting to avoid “environmental catastrophe” in the region, which was described by one expert as an area of “immense biological, cultural and economic importance”.

Experts welcomed the news that the Solong was not carrying the poisonous substance sodium cyanide but feared the highly potent jet fuel could be a “disaster” for local marine life.

Dr Simon Boxall, an academic in oceanography at the University of Southampton, said the Jet A-1 fuel had a “much higher toxicity” than crude oil and that “the impact of that on life in the oceans would be devastating”.

Specialist pollution-control vessels from Germany and Norway arrived at the scene on Tuesday to try to measure the scale of the spillage and contain any toxins.

Dr Jennifer Allan, an expert in global environmental politics at Cardiff University, said it was a “disaster in every sense of the word”.

“The health and environmental effects will be short- and long-term, local and regional,” she said. “The jet fuel will be harmful to local wildlife and beaches and the livelihoods that rely on them. In the long term, it could move up the food chain; for example, from fish into birds and people.”

Investigators were expected to speak to many of the 36 crew members rescued from both ships in the coming days to try establish what went wrong.

Maritime experts suggested human error was likely to have played a significant role in the incident but that a technical mishap or oversight could not be ruled out.

DCS Craig Nicholson of Humberside police said the force had “taken primacy for the investigation of any potential criminal offences which arise from the collision between the two vessels”.

He added: “Following inquiries undertaken by my team, we have arrested a 59-year-old man on suspicion of gross negligence manslaughter in connection with the collision. This follows the conclusion of search operations by HM Coastguard for the missing crew member of the Solong.

“Our thoughts are with the family of the missing crew member, and I have appointed family liaison officers to make contact and provide support to the family.

“The man arrested remains in custody at this time whilst inquiries are under way, and we continue speaking with all those involved to establish the full circumstances of the incident.”

The cost to repair the ships, let alone the cost of any environmental damage or cleanup, is expected to run into the tens of millions of pounds.

Harj Narulla, a barrister specialising in climate and environmental justice at Doughty St Chambers, said Stena could sue the Solong’s owner if it was found to be responsible.

Costs would include damage to the tanker and cargo ship, as well as loss of the value of cargo, loss of earnings and income as well as repair costs.

Environmental damage costs would depend on how much was spilled, which chemicals and how much was contained after the spill.
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