Joan Rivers died from 'low blood oxygen'

Comedian Joan Rivers died from low blood oxygen during a routine medical procedure to check out voice changes and reflux, the New York City medical examiner's office has ruled.

The 81-year-old died on Septemebr 4 after suffering brain damage during a procedure to examine her gastrointestinal tract and vocal folds.

Joan Rivers pictured in 2010. Credit: Reuters

Rivers had been sedated during the procedure with the anaesthetic propofol, the medical examiner said.

Her daughter Melissa declined to comment on the findings, saying in a statement: "We continue to be saddened by our tragic loss and grateful for the enormous outpouring of love and support from around the world."