Carrie Fisher died of sleep apnoea and other factors, the Los Angeles County Coroner's Office said.

In a statement, the coroner's office recorded several issues that contributed to Ms Fisher's death, including a buildup of fatty tissue in the walls of her arteries.

While autopsy the coroner said "multiple drug intake" was how the "injury occurred" but its significance could not be determined and investigators could not determine an exact cause of her death in December 2016.

In a statement to US entertainment website People, daughter Billie Lourd said: "My mom battled drug addiction and mental illness her entire life. She ultimately died of it.

"She was purposefully open in all of her work about the social stigmas surrounding these diseases."Fisher

Sleep apnoea causes the walls of the throat to relax during sleep, interrupting normal breathing, according to the NHS.

The actress, best known for playing Princess Leia in the Star Wars franchise, died on 27 December 2016 aged 60.

She had recovering after suffering a heart-attack on a flight from London to Los Angeles just days before.

Her mother, Debbie Reynolds, died two days later after suffering a stroke.