PURNEA, June 11 -- A 55-year-old undertrial prisoner lodged at Kishanganj district jail died allegedly by suicide on Wednesday morning, police said. The woman's family has demanded a fair probe into the incident, alleging custodial assault led to her death. According to police, Usha Rani, 55, a resident of Kochadhaman in Kishanganj, had been in jail since February after being charged under Dowry Prohibition Act at Kochadhaman police station. Jail superintendent Dharmendra Kumar said, "Rani was found hanging near the toilet and it was spotted by the warden who later informed it to other jail authorities. She was rushed to the district hospital where the doctor declared her dead." Jail authorities claimed that the woman was being treated for mental illness at MGM Medical College and Hospital and jail administration was monitoring her illness and well-being. The woman's family demanded an impartial inquiry into the incident. "We can't rule out the possibility of torture inside jail leading to her death," Ajay Prasad Sinha, Rani's husband, said. "The woman's family members have been handed over the body after post-mortem for last rites. We are waiting for the autopsy report and an investigation is underway," Kumar said....