One of three suspects in the murder of a man stuffed in a concrete-filled barrel found in Chon Buri has been arrested in South Korea.

The man in his 20s was arrested at his house on Sunday evening in Gyeongnam province, the Yonhap news agency reported on Monday.

"Details of the case cannot be disclosed as it is currently under investigation," a police official was quoted as saying.

The man is one of the three suspects in the death of a man found in a big plastic barrel dumped in Map Prachan reservoir in Bang Lamung district in Chon Buri. The barrel was also filled with concrete and was found by divers searching the reservoir bed on Saturday evening. The reservoir is not far from Pattaya.

The victim is believed to be Roh Eui Jong, 34, reported missing since May 3 when he was allegedly abducted by three Koreans.

Police are still confirming the victim's identity.

Police sources said on Sunday all three suspects had left Thailand. One of them returned to South Korea. Another had crossed illegally into Myanmar and the third into Cambodia.

Gyeongnam province is in southeastern South Korea. Its capital is Changwon.