A middle-aged couple, saddened over the demise of their 10-year-old son six months ago, committed suicide by drinking poison in Madhavaram on Saturday. Hari, the only child of the couple, had died mysteriously after he underwent treatment for a knee problem.

Indira Kumar (46) was working as maintenance personnel in a private company in Manali and his wife Lakshmi (40) as a government school teacher in Madhavaram. After several years of married life Lakshmi conceived and gave birth to a boy 10 years ago, police said.

All of a sudden, Hari developed a knee problem and his parents took him to a private hospital for treatment. But the boy died after a week. The couples’ relatives informed them that the doctors could not identify cause of death.

The couple decided to shift the house after Hari’s death due to grief. After shifting to Telephone Colony in Madhavaram, Indira Kumar's mother Chandra (70) also lived with them.

Chandra went to temple on Saturday morning at 9.30 am and on her return she found the dead bodies of Lakshmi, who was on the bed, and Indira Kumar, who was on the floor, following which she alerted the Madhavaram police immediately.

The couple was found to have consumed poison on investigation. A suicide note, found written by them, said that they were dejected over their son's death.