Source: Joan Rivers' doctor takes selfie during surgery

NEW YORK (KTRK) -- More details are starting to emerge about what happened during Joan Rivers' vocal cord procedure that ultimately resulted in her death.

According to a source close to the investigation, a staff member at Manhattan's Yorkville Endoscopy claims Rivers' personal doctor took a selfie with the star was sedated.

The source, who has not been identified, says the doctor then performed a biopsy on Rivers without her prior consent. Rivers, 81, was at the clinic for a scheduled endoscopy by another doctor, gastroenterologist Dr. Lawrence Cohen. That procedure was intended to help diagnose her hoarse voice and sore throat. It involved the insertion of a camera down her throat.

That's when investigators believe Rivers' vocal cords swelled, leading to cardiac arrest. Rivers was rushed by paramedics from Yorkville Endoscopy to New York's Mount Sinai Hospital, where she died a week later.