A doctor attending Joan Rivers reportedly stopped to take a selfie in the procedure room while the famous comedienne was under anaesthesia, just moments before she went into cardiac arrest.
The physician hasn't been publicly identified, but is believed to be Rivers' personal ear-nose-throat doctor, reported CNN.
A member of staff at Manhattan's Yorkville Endoscopy clinic told investigators about the physician's questionable behaviour, a source close to the death investigation said.
Rivers, 81, had checked in for a routine throat procedure at the Yorkville Endoscopy clinic in Manhattan on August 28, when her condition took a shocking turn for the worse.
First the clinic's medical director Lawrence Cohen carried out a scheduled endoscopy.
The procedure was intended to help diagnose her hoarse voice and sore throat and it involved the insertion of a camera down her throat.
After Cohen had finished his work, a biopsy was allegedly done on Rivers without her prior consent.
Rivers' vocal chords began to swell during the allegedly unauthorised biopsy, cutting off the flow of oxygen to her lungs, which led to cardiac arrest on the morning of August 29.
Rivers was then taken from the clinic to Mount Sinai Hospital a mile away, where she died a week later.
