A retired college professor, his wife, daughter and a relative were found dead at their home here in Kerala, police said on Sunday.

While three bodies were found in a charred condition, another mutilated body was found wrapped in a bag in their home, located a stone's throw away from the residences of Chief Minister Pinarayi Vijayan and eight of his cabinet colleagues.

The son of the couple, Kedal Jaison, 30, who resides in Australia and was here since some time is reportedly missing. Police are treating him as a suspect.

The deceased were identified as Professor Raj Thankam, his wife Jean Padma -- a retired medical superintendent of the General hospital here, their daughter Carol -- a medical student, and aunt Lalitha.

Police said the neighbours on late Saturday night saw smoke coming from the house and the fire brigade was alerted. It was only after the fire fighters came and doused the fire that they discovered the bodies.

Inspector General of Police Manoj Abraham, who visited the crime spot, told media that the bodies were in a decomposed state and it was surmised that they were killed three-to-four days ago. The post-mortem would have to be done at the spot by forensic experts, he added.

A relative of the family told media that Jaison had informed them that his parents have all gone for a tour and would not be back for a week.

Meanwhile, the police said they had received information that someone was seen running away from the house on Saturday night and they believe that it was Jaison.