A WOMAN and her three-year-old son were killed Tuesday in what police say is possibly a revenge killing involving the wife of a commune official.

Sou Veasna, 32, and her child, Sak Ronan, were found dead in Dangkor district's Kakab commune, commune police chief Born Sam Ath told the Post.

Both has been slashed with a knife, police said.

The dead woman's older brother, 49-year-old Kum Sok, was also severely wounded in the attack and may not survive, Born Sam Ath said, adding that the victim was suffering from severe head wounds.

"According to my investigation of the scene, the murdered woman is the second wife of a Kandal provincial commune chief, so maybe his wife is involved in the attack," Born Sam Ath said.

"It was a very brutal murder. The murderers even killed a boy," he added.

Born Sam Ath said district police were cooperating with provincial authorities to investigate the killings.

 "We are now actively cooperating in the investigation for the murderers, although they may have escaped to other provinces," he said.

Chan Soveth, a senior monitor with the Cambodian rights group Adhoc, told the Post on Wednesday that his organisation was monitoring the investigation.

"We will keep an eyes on the police action," he said.

"It is very shocking news that offenders have not only killed a mother, but a boy," Chan Soveth added.

Chan Soveth said since the attack was not politically motivated, he was not actively involved in the probe.