Joan Rivers’ doctor was reportedly performing an unauthorized biopsy at time of emergency

A mid-proceduce decision to biopsy Joan Rivers’ vocal chords set off a chain of medical emergencies that eventually resulted in her death, a medical source with knowledge of the case told The New York Daily News.

According to the source, the Fashion Police host only approved of an endoscopy when she arrived at Yorkville Endoscopy, an outpatient facility, on Aug. 28. During the procedure, a doctor who arrived with Joan and is not employed by Yorkville Endoscopy asked if he could use the clinic’s instruments to examine “something” on Joan’s vocal chords.

“He asked and they let him… A huge no-no,” said the source. “A biopsy like that should only be done in a hospital setting.”

During the unauthorized procedure, Joan experienced a laryngospasm, which cut off her air supply. She was rushed to Mount Sinai Hospotal, but never recovered.

State Health Department spokesman James O’Hare said they are “investigating the matter.” A spokesperson from the clinic publicly denied any wrongdoing and said the facility “has the same level of life-saving and resuscitation devices (such as state-of-the-art cardiac defibrillators, airway management equipment, etc.) found in any hospital emergency room or hospital-based operating room.”