Kannur (Kerala): A woman was arrested on Tuesday after she confessed of killing her parents and her nine-year-old daughter by poisoning them in a gap of four months this year, police said.

Police cracked the crime after a 13-hour-long questioning of Soumya, 28.

Soumya was taken for questioning when she was convalescing at a state-run hospital near the city after being admitted for nausea and indigestion - incidentally, the same symptoms that her parents and her elder daughter suffered before they died.

While her mother died on March 7, her father passed away on April 13, her daughter died on January 31. However, following a complaint from a relative, the body of the child was exhumed after rat poison was found in the viscera of her parents.

According to police, Soumya however, denied of any role in the death of her one-year-old daughter in 2012.

Incidentally, this incident happened in the home village of Chief Minister Pinarayi Vijayan and it was only after his intervention did the police speed up their investigation.

The woman was separated from her husband and according to police, her motive was that her parents and child were "impediments to her wayward life".