Two oil tankers have been detained on suspicion of carrying out ship-to-ship transfer of crude oil worth more than RM512 million about 24 nautical miles west of Muka Head, Penang last Thursday, the Malaysian Maritime Enforcement Agency (MMEA) said on Saturday.

The Malaysian agency said a patrol boat received a report at about 1 a.m. local time that two oil tankers were suspected of conducting oil transfer activities.

The two vessels are believed to have carried out ship-to-ship crude oil transfer activities involving 53 crew members.

The seized tankers were carrying 53 crew members comprising Chinese, Myanmar, Iranian, Pakistani and Indian nationals.

The value of the seized crude oil exceeded RM512 million, while the value of both oil tankers amounted to RM718 million, the agency said.

The two ship captains and their vessels have been detained and handed over to Penang Maritime investigation officers for further action under existing legal provisions.

The case is being investigated for anchoring without permission from the Director-General of the Marine Department.

It is also being probed for conducting ship-to-ship transfer activities without approval from the Marine Department of Malaysia.

The authority said they will continue to intensify patrols in state waters to ensure all maritime activities comply with the law.