A family of four, one a 5-year-old girl, have been found dead with savage knife wounds at a rubber plantation in Bang Saphan Noi district, Prachuap Khiri Khan.

The bodies were discovered at a warehouse, which also serves as living quarters for workers, at a rubber plantation in tambon Chang Raek, said Pol Capt Charin Duang-ied, a deputy investigation chief at Bang Saphan Noi police station.

The crime was reported at around 6 pm on Tuesday.

All the victims were of the same family. Three were found dead inside the first room of the living quarters. They were Namphon Khamkhong, 30, his wife Mukda Ngokwisai, 27, and their daughter Nararak Khamkhong, 5.

In a savage attack, the couple had had their throats slashed, while the girl had knife wounds to her face, body and her right arm. The body of the fourth victim, identified as Namphon's father Prasong Khamkhong, 50, was found with his throat slashed about 40 metres from the warehouse.

Two knives and a sickle were found at the scene. A doctor who examined the bodies said they had died at least 24 hours before being discovered.

The plantation owner, Pornnipa Sae Liang, 29, found the bodies and alerted police. She said the victims worked for her. They had been employed there for about a month and stayed in the living quarters, together with two Mon migrant workers. The two Mon workers have disappeared.

Police suspect the victims had quarrelled with the migrant workers. They were investigating.