Joan Rivers' cause of death revealed

Joan Rivers' cause of death has been revealed, a month after the comedian passed away.

The New York City medical examiner's office has ruled that the star died as a result of brain damage caused by lack of oxygen.

Joan Rivers passed away on 4 September

Joan, 81, died on 4 September after being on life support for a week at Mount Sinai hospital after she stopped breathing and suffered a cardiac arrest during surgery on her vocal chords at a nearby private clinic.

The death was classified as a "therapeutic complication", which means it was a known risk of the procedure.

The medical examiner listed the official cause of death as anoxic encephalopathy due to hypoxic arrest - a condition caused when brain tissue is deprived of oxygen leading to brain damage.

Melissa Rivers, Joan's daughter and TV partner, said she had no comment on the ruling.

"We continue to be saddened by our tragic loss and grateful for the enormous outpouring of love and support from around the world," she said in a statement.