Kannur (Kerala) | Police probing the death of four members of a family in Ramanthali here have found that two children were poisoned before their father and grandmother died by hanging, officials said on Tuesday.

Police found Usha K T (56), her son Kaladharan K T (36), and his children Hima (6) and Kannan (2) dead at their residence on Monday night.

Payyannur police registered a case of unnatural death and launched an investigation.

A police officer said the postmortem examinations of the deceased were completed and revealed that the two children were administered poison. "Subsequently, Kaladharan and Usha also consumed poison and later died by hanging," the officer said.

Police said a suicide note was recovered from the house, which indicated marital issues faced by Kaladharan and the family.

According to police, Kaladharan and his wife had been living separately for the past eight months.

The family court had granted custody of the children to the wife.

However, the children reportedly wished to stay with Kaladharan and had returned to his house only recently, the officer said.

Police officials said that following a complaint lodged by Kaladharan's wife against his father Unnikrishnan, a case had been registered under the Protection of Children from Sexual Offences (POCSO) Act. She had alleged that Unnikrishnan had misbehaved with the children, they said.

As per the bail conditions, Unnikrishnan was staying with relatives away from the children and was not present at the house when the four were found dead.

The bodies were handed over to relatives after postmortem on Tuesday, police said.