The panel comprises representatives of the Marine Police and the Army.

The tanker has returned to Thailand with its crew unharmed.

The CP41 was robbed off the Malaysian city of Kuantuan en route from Singapore to Shell’s oil depot in Songkhla province. It was carrying 3.8 million litres of diesel oil.

Tankers dock at Noo Island off Songkhla.

Krissana said the investigation into the incident was ongoing and the nationality of the pirates, and whether any Thais were involved in the robbery, was unclear.

However, he said the pirates did not communicate with one another in Thai with a source saying they spoke in Bahasa.

Vice Admiral Pornchai Pinthong, commander of the 2nd Naval Base, said the robbery took place at just after 9pm on Saturday night when the CP41 was in Malaysian waters at latitude 03.55.27 and longitude 103.52.81.

He said six or seven pirates went aboard and rounded up the captain and 16 other crew.

They destroyed the ship security alert system, robbed the crew of their valuables, stole the oil and fled.

Pornchai said the Thai Navy had contacted the Malaysian Navy in a bid to locate the pirates.