More tests needed to determine cause of Carrie Fisher's heart attack

Carrie Fisher's death certificate has confirmed that the Star Wars actor and Hollywood screenwriter died of a heart attack, but says more tests are needed to find out what caused it.

The Los Angeles County death certificate, obtained by The Associated Press news agency, states under the "cause of death" heading: "Cardiac arrest/deferred."

The "deferred" designation indicates that further investigation is needed, usually in the form of toxicology tests that can take several weeks to complete.

Fisher, 60, who played Princess Leia in the Star Wars films, suffered the heart attack on a flight from London to Los Angeles on December 23 and died on December 27 at Ronald Reagan UCLA Medical Centre.

Her mother, Singin' In The Rain star Debbie Reynolds, 84, died a day later.

The death certificate lists Fisher's daughter Billie Lourd as the notifying party and gives Fisher's occupation as "writer".