The Spanish Formula 1 reserve racing driver Maria de Villota died from natural causes, according to a post-mortem examination.
"I can confirm that her death was due to natural causes. The family has been informed," Dr Joaquin Lucena Romero, head of forensic services at the Institute for Legal Medicine, said.
De Villota, 33, was found dead in a hotel room in Seville, Spain on Friday 11 October.
Investigators said they had "not found any drugs or signs of violence", adding that "everything points to a death by natural causes".
The top female racing driver lost her right eye in a crash in July 2012 while testing for the Marussia team.
She suffered severe head and facial injuries after the bizarre accident, colliding with a lorry at Duxford Aerodrome, Cambridgeshire.
De Villota's car, travelling at up to 40mph, ran into an articulated trailer with eyewitnesses saying they saw it suddenly accelerate.
The 33-year-old not only lost her eye but also needed many operations to repair the damage to her face and skull.
De Villota, daughter of ex-Formula 1 driver Emilio, was reported to have been in Seville to launch her autobiography.
Tributes poured in from the world of motor racing. Eddie Jordan BBC F1 chief analyst, in Suzuka: "She was a wonderful figurehead. She showed the world how she was going to beat [the setback of her horrific crash], find a new life and come back to motor-racing and she's written this great book."
Britain's Jenson Button added: "It's horrendous news. Very tragic, the girl has been through so much, more than most people go through in their lives. It has been tough for her but this is horrific news and a real shock to the whole paddock and the world of motorsport."