Thai authorities have found about 32 mass graves suspected to be of Myanmar and Bangladeshi migrants in a jungle camp which is frequented by human traffickers.
At least 30 of the remains have been recovered from a shallow graveyard in a remote and rugged mountain area near the border with Malaysia.
Authorities have also rescued a lone survivor during a raid and he is said to be "very sick".
"Today, 88 policemen trekked to the camp for an hour into the jungle. We found 34 shelters, including bedrooms, restrooms and a kitchen. It looked like [the camp] had recently been abandoned," said Colonel Weerasant Tarnpiem.
"The police found a survivor named Thu Don Kha, 26, a Bangladeshi citizen, who was sick. He told the police there were over 100 Rohingya detained in the camp. The police also found a dead man and more than 30 graves of Rohingya, both older and newer."
The police believe the victims, mostly smuggled in by human traffickers, were starved to death.
Investigators are examining the bodies to identify the victims and establish their nationalities. Since most of the corpses have badly decayed, it would take time, they say.
"There are 32 graves, four bodies have now been exhumed and are on their way to hospital for an autopsy. The bodies were all decayed. More bodies are expected to be found," rescue worker Sathit Kamsuwan was quoted as saying by the Thai daily, The Nation.
"It is believed that the graves were of those who died during the journey. After the bodies are exhumed, there will have to be autopsies to determine the causes of the death."
The process of exhuming the bodies has been temporarily suspended due to rain and will resume shortly. The graves have been found shortly after the arrest of several Rohingya in the same district.