A Russian national was revealed to be the captain of the cargo ship that collided with a U.S. tanker off the coast of England in an incident that sparked a massive fire, spilled jet fuel into the sea and left one person feared dead. 

The 59-year-old man remained in United Kingdom police custody Wednesday after being detained on suspicion of manslaughter by gross negligence, according to Ernst Russ, the owner of the Portugal-flagged Solong cargo ship. It added that the ship’s 14 crew members were a mix of Russian and Filipino nationals. One of them remains missing and is presumed dead. 

The Solong collided Monday with MV Stena Immaculate, a U.S.-flagged tanker transporting jet fuel for the American military. U.S.-based Crowley Ship Management said the MV Stena Immaculate was anchored near Hull when it was struck and that all 23 onboard are "safe and accounted for" with no reported injuries. 

Leading up to the collision, the Solong was inspected in Dublin, Ireland last July and was found to have 10 deficiencies, according to the Associated Press.  

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Port inspection documents show the Solong failed steering-related safety checks with the vessel's "emergency steering position communications/compass reading" unreadable. It also had "inadequate" alarms, survival craft "not properly maintained" and fire doors "not as required." 

Then a second inspection in Scotland in October found two more deficiencies, but the ship wasn’t detained after either inspection, the AP reported. 

However, U.K. authorities said they don’t suspect foul play in the crash. 

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The 596-foot Stena Immaculate was operating as part of the U.S. government’s Tanker Security Program, a group of commercial vessels that can be contracted to carry fuel for the military when needed. 

"Crowley continues to work closely with U.K. agencies to support the incident response, salvage and environmental impact mitigation operations resulting from container ship Solong striking the Crowley-managed tanker Stena Immaculate while at anchor on Monday, March 10," the ship’s owner said Tuesday. 

"It remains uncertain at this time what volume of fuel may have been released as a result of the incident, but initial review shows impacts have been limited due to exposure to the fire and evaporation of the Jet A1 fuel," Crowley continued. "In addition, U.K agencies are closely monitoring air quality and any possible public health impacts resulting onshore. Both are currently measuring low or within normal levels." 

The Solong was drifting and still on fire Wednesday, but is likely to remain afloat rather than sinking, officials said. 

The Associated Press contributed to this report.