The footprints of an adult and young tiger were found near the scene where 44-year-old Hyaya Seng was found dead Thursday at the plantation in a mountainous area of Yala province near the border with Malaysia.
"The victim lost his head and suffered deep cuts to his stomach and scratches all over his body," deputy district chief Urupong Chanakul told AFP.
He said another suspected tiger attack took place in a nearby village last year.
Thailand, a hub of international smuggling, is one of just 13 countries hosting fragile tiger populations. Fewer than 300 tigers remain in the wild in Thailand, according to wildlife group WWF.
Rubber tappers in the deep south are also often targeted by suspected Muslim insurgents who sometimes behead their victims.