Marine police in southern Vietnam have seized a Thai vessel for smuggling oil in Vietnam’s exclusive economic zone.

The officers caught the ship off the southwestern coast last Saturday, when its 11 crew members were moving diesel to a Vietnamese boat.

The Thai boat reportedly carried around 130,000 liters of diesel at the time and its Thai captain failed to produce legal documents for the fuel.

Marine police on Tuesday said they are still keeping both vessels and their crew members at Phu Quoc Island for investigation.

Vietnamese coast guards in July also caught two Thai boats smuggling fuel to two Vietnamese fishing boats in the southwestern waters off Phu Quoc Island.