The ReCAAP reporting centre said the 3,200-dwt Srikandi 515 (built 2013) had been identified off Narathiwat province on 27 November.
The ship was heading to Gresik from Kalimantan with 3,100 tonnes of palm oil when it was seized off Indonesia on 9 October.
Thai authorities arrested eight Indonesians armed with knives and machetes on the vessel, which had been repainted so its name showed as Chong Li 2.
It had reportedly run out of bunkers and was looking to refuel.
The palm oil cargo was apparently left intact.
The tanker has been escorted back to Songkhla in Thailand for further investigation.
The vessel left port on 8 October, but by 17 October it had not reached its destination.
The captain and 10 crew aged between 24 and 45 were later picked up by Malaysian fishermen safe and well after having been dumped into lifeboats by the attackers.
They had been held captive for 13 days, they said.
The ship is listed as owned by Lima Srikandi Jaya of Jakarta.
