Anne Heche has died in hospital a week after her horror car crash in Los Angeles. She was 53.

The US actress had been in a coma since the accident on August 6, with her representative saying yesterday she was being kept on life support to "determine if her organs are viable".

Hours before Heche's death, her family released a statement saying the star was "not expected to survive."

"Unfortunately, due to her accident, Anne suffered a severe anoxic brain injury and remains in a coma in critical condition," Heche's family said in a statement, obtained by People. "She is not expected to survive."

Anne Heche poses for a portrait to promote the film The Last Word. Photo / AP

Heche's family went on to thank wellwishers for their support over the last few days, before talking about the star's legacy.

"We want to thank everyone for their kind wishes and prayers for Anne's recovery and thank the dedicated staff and wonderful nurses that cared for Anne at the Grossman Burn Center at West Hills hospital," the statement said.

"Anne had a huge heart and touched everyone she met with her generous spirit. More than her extraordinary talent, she saw spreading kindness and joy as her life's work — especially moving the needle for acceptance of who you love.

"She will be remembered for her courageous honesty and dearly missed for her light."

It comes after police confirmed on Friday that Heche tested positive for cocaine and possibly fentanyl at the time of her crash.

Los Angeles Police Department sources told TMZ that the actress' blood test results came up positive for both substances.

However, the law enforcement insiders cautioned that fentanyl may have been administered to Heche at the hospital to help manage her pain after the accident, so they will do more testing to determine whether the fentanyl was in her system at the time of the crash.

The Six Days Seven Nights actress, who dated Ellen DeGeneres in the '90s, was in an "extreme critical condition" following the collision in Mar Vista, which saw the actress pulled from her vehicle after it burst into flames after crashing into a home.

 

-  Lexie Cartwright and Benedict Brook, news.com.au