Thai authorities are working to ensure there is no oil leak from a floating storage and offloading (FSO) unit that suffered water ingress.

A crew member on the vessel died earlier this week when water leaked into the 106,000-dwt Benchamas 2 (built 1999), owned by Malaysian shipping company MISC Berhad, Reuters reported.

The FSO is carrying 400,000 barrels of crude.

The incident was blamed on a seal malfunction that developed during maintenance work.

Navy spokesperson Admiral Prokgrong Monthatphalin said multiple agencies were working to recover the body of the dead seafarer, fix the leak and avert an oil spill.

“The vessel’s condition is stable and weather conditions are not interfering with the rescue operations. However, there is no electricity in the engine room … it is affecting assessment of the situation,” he added.

The FSO is operated by a unit of Chevron. It has a storage capacity of 650,000 barrels and operates at the Benchamas field in Block B8/32 in the Gulf of Thailand.

It is located about 207 km off Sattahip in Chon Buri province.

Chevron expressed sadness at the death of the crew member, a contractor, and said all non-essential personnel were being removed from the vessel.

“The safety of all personnel and the protection of the environment remain our top priorities. We have engaged and notified the relevant authorities and are working with all stakeholders,” the oil company said.

The Benchamas 2 was ordered for $41m in 1997 as an aframax tanker. It was built at Hyundai Heavy Industries.

A spill from an undersea pipeline operated by Star Petroleum Refining in the same region in January 2022 leaked an estimated 50,000 litres of oil.