The Vietnamese Embassy in Malaysia has contacted Malaysian Maritime Enforcement Agency (MMEA) and local authorities to clarify the incident, verify the fishermen's personal information as well as that of the two vessels on which they had fared, Foreign Ministry spokeswoman Le Thi Thu Hang told VnExpress on Wednesday.

Hang said Vietnam also requested Malaysian authorities to treat the detained fishermen humanely and provide enough evidence proving the two vessels had indeed illegally encroached Malaysian waters so Vietnamese authorities could launch an investigation and deal with the boat owners.

The Bernama state news agency quoted a source from MMEA saying the two fishing boats carrying 16 crew members were detained off Terengganu state, on the east coast of peninsular Malaysia, on Jan. 23.

The fishermen, aged 18 to 62, did not have any valid identification documents nor possessed any license to fish in the country’s waters, Terengganu MMEA Director Captain Muhammad Suffi Mohd Ramli was reported as stating.

"Two boats, fishing gear, catch and diesel supply were also seized, with the total haul valued at RM3 million ($741,685)," he added.

The fishermen were taken for novel coronavirus swab tests before being detained. They are being investigated under Malaysia's Fisheries and Immigration acts.