Dr Anahita Pandole had not properly worn the seat belt of the car, which she was driving at the time of the accident that claimed the life of industrialist Cyrus Mistry earlier this year, police said on Friday.
Former Tata Sons chairman Mistry (54) and his friend Jehangir Pandole were killed after the Mercedes-Benz car hit the railing of the Surya river bridge in Palghar district of Maharashtra on September 4.
Dr Anahita, who was at the wheel, and her husband Darius suffered serious injuries in the accident. All of them were returning to Mumbai from Ahmedabad.
"Dr Anahita, who was driving her Mercedes-Benz car, had not worn the seat belt properly as the pelvic belt was not fastened," Palghar Superintendent of Police Balasaheb Patil said.
"She had only worn the shoulder harness from the back and had not adjusted the lap belt," he added.
These findings are part of the chargesheet, which the police will file before the court, he said, adding the police were waiting for Anahita, a gynaecologist, to get discharged from a Mumbai-based hospital.
Dr Anahita, who escaped with injuries in the accident, has been undergoing treatment at a private hospital in south Mumbai and likely to be discharged in the next couple of days, he said.
The Palghar Police had registered a case against her in November.
The offence was registered under the Indian Penal Code (IPC) sections 304 (A) (causing death by rash and negligent act), 279 (rash driving on a public road) and 337 (causing death by act endangering life and personal safety of others) besides the Motor Vehicles Act at Kasa police station in the district.