The graveyard was found to have the decomposed bodies of 33 people, believed to be Rohingya migrants.
The finding came after Thai border authorities were alerted by a Malaysian national that a large graveyard had been found on the Thai side of the border near the Malaysian town of Padang Besar.
Police and district officials went to inspect the area and found 33 tombs where the bodies were buried.
Another decomposed body was also found lying unburied.
Investigations later revealed that the area was earlier used by some 200-300 Rohingya migrants who smuggled into the country, and lived there.
Villagers said these migrants died of sickness and some died fighting after having quarrels among themselves.
However as the authorities arrived at the area today, the area was left vacant and all Rohingya migrants had escaped, believed to have crossed the border into Malaysia.
Royal Thai Police commissioner Pool Gen Somyot Phumphanmuang confirmed the graveyard finding and said it was used as a detention centre by human traffickers.