Autopsy and toxicology reports have shown that the late Anne Heche wasn't under the influence of illegal substances at time of her death.
The actor was declared brain dead aged 53 after a critical car crash in August.
Although there was a trace amount of cocaine found in her blood sample after the accident, an autopsy report has confirmed that she used the drug days before her death.
There was also evidence of cannabinoid and benzodiazepine found in her urine sample, suggesting that she had taken those drugs in the days leading up to the accident, since neither substance appeared in her blood sample.
Toxicology reports from the LA County Medical Examiner-Coroner Office, seen by the Los Angeles Times, also found traces of Fentanyl in Heche's urine sample, though that was consistent with a treatment that was administered in the hospital for pain.
Anne Heche had been driving around LA in her Mini Cooper on 5 August before she crashed the car into her home.
Authorities understood at the time that her vehicle potentially hit a kerb and was launched two feet off the ground.
The crash resulted in a fire that subsequently destroyed an LA home.
Anne Heche was rushed to the emergency room at Ronald Regan UCLA Medical Centre, before being transferred to a burn unit for her injuries.
Due to a lack of oxygen immediately after the crash and the fire, Anne suffered a 'severe anoxic brain injury', as well as severely bad burns, according to a statement released by her family.
After a week in a coma, she was declared brain dead on 11 August, though her body was kept on life support until 14 August so her organs could be donated.
Immediately after the accident authorities began investigating Anne for the misdemeanour charges of DUI and hit and run, though this was later upgraded to a felony.
However, according to toxicology reports, Anne had no alcohol in her system at the time.
Heche was known for her roles in films including Psycho, Six Days, Seven Nights, I Know What You Did Last Summer, Donnie Brasco and Cedar Rapids as well as TV roles in medical drama Nip/Tuck.
She is also known for her role on the soap opera Another World, for which she won a Daytime Emmy in 1991.
If you have experienced a bereavement and would like to speak with someone in confidence contact Cruse Bereavement Care via their national helpline on 0808 808 1677.
- Coroner has released Anne Heche's cause of death after conducting autopsy
- Actor Anne Heche’s family ask for prayers as she recovers from massive car crash
- Police Find $1.6 Million Of Marijuana In Illegal Grow Operation Home
- Last day of high school video from the 90s shows how things have massively changed