An oil palm plantation owner was robbed and murdered at his house in Nakhon Si Thammarat, where he lived alone, police said on Monday.
Muang Nakhon Si Thammarat police station was alerted to the killing of Muek Maikaew, 73, on Monday morning.
He was found naked, with knife-inflicted wounds to his head and face.
A doctor determined that he had died at least six hours earlier.
She said her father had lived alone in the house, and that he had regularly earned tens of thousands of baht each month from the sale of palm oil.