JOHOR BARU, MALAYSIA - Another two vessels have been detained by the Malaysian Maritime Enforcement Agency for illegally transferring oil here after a similar case on Sunday.

The agency's Tanjung Sedili district head, Abdul Hadib Abdul Wahab, said authorities had found the two ships positioned close to one another off the Tanjung Kapal coast during their rounds at about 10.20am on Monday.

He said the agency found that no permit or document had been issued to allow any oil transfer activity between the two vessels.

'Neither ship was able to produce valid ship-to-ship activity permits. We suspect that some 565,000 litres of marine gas diesel were illegally transferred,' he said, adding that the captains of both vessels had been arrested.

He said the agency had also confiscated the identification documents of all 19 crew members onboard.

The ships were registered in Singapore and Penang.

Failing to inform the Marine Department of ship-to-ship activity in local waters carries a fine of up to S$42,220, two years' imprisonment or both.