The last known location of the 3,800-dwt Orapin 4 (built 1983) was four miles north of Pulau Batam on 27 May, the ReCAAP information sharing centre said.
The Thai International Tankers ship had left Singapore for Pontianak in Indonesia with 3,377 tonnes of diesel.
It was scheduled to arrive on Thursday, but never made it.
On Wednesday, the owner tried to contact the vessel by email but heard nothing back.
The
