The Malaysian Maritime Enforcement Agency (MMEA) intelligence found that 13 criminals were involved in the hijacking of the oil tanker, MT Orkim Harmony, on June 11.

The agency's deputy director-general (Operations), Vice-Admiral (Maritime) Datuk Ahmad Puzi Ab Kahar said five of them had used a tugboat to approach the tanker, while the other eight went up the vessel.

He said the Indonesian authorities had informed that the tugboat, believed to be used by the suspects to hijack MT Orkim Harmony, was found in Batam two days ago.

"We had contacted the Indonesian authorities on our hunt for the remaining five hijackers," he said at a press conference on developments involving the tanker, here, today.

Eight of the alleged hijackers of MT Orkim Harmony, which was carrying 6,000 tonnes of RON95 petrol worth RM21 million, were arrested by the Vietnamese authorities near Tho Chu Island, southern Vietnam, last Friday.