According to police, the incident took place at 4:15 pm when Sushila reached the police headquarters main gate, poured an inflammable liquid and suddenly set herself on fire.
"The policemen present at the gate immediately swung into action and used a blanket to douse the flame. A constable, identified as Vikramjit sustained burn injuries on his forearms in the rescue act," said a police official.
"Both of them were rushed to LNJP hospital where the constable was discharged after first aid and the woman, who sustained 45 per cent burn injuries, is being treated," he said.
"The woman had approached police of the Southwest district around three days ago as she had an issue with her sister. Sushila lives on the first floor whereas her mother and a sister on the ground floor of their house. Her husband stays in Madhya Pradesh for work," he said.
Police had tried to settle the issue as it was a family matter and did not initiate any legal action, the official said, adding that further probe was on in the matter.