CNN: Joan Rivers's Doctor Took Selfie, Performed Unauthorized Biopsy

.

(Splash News/Getty Images)

Joan Rivers's personal doctor began to perform an unauthorized biopsy on the 81-year-old just before she went into cardiac arrest, CNN reports.

And another disturbing detail has emerged: An unnamed Yorkville Endoscopy Clinic staffer also told the news organization that the doctor — described as Joan's personal ear-nose-throat physician — reportedly took a selfie while Rivers was under anesthesia.

Rivers was at the clinic for a scheduled throat procedure by another doctor, gastroenterologist Dr. Lawrence Cohen. When he was finished, the comedian's personal doctor (whose name has not been released) reportedly began to perform a biopsy without her prior consent, according to CNN. The ENT was not certified to perform procedures at the Manhattan clinic, as required by law, says CNN.

"Investigators believe that Rivers's vocal cords began to swell during the allegedly unauthorized biopsy, cutting off the flow of oxygen to her lungs, which led to cardiac arrest on the morning of August 29," the source said.

[Related: Joan Rivers's Star-Studded Funeral]

An investigation into what led to Rivers's death continues. However, this new information contradicts the clinic's previous statements: Yorkville Endoscopy last Thursday denied reports that any vocal cord biopsies had been performed there.

Dr. Cohen, the medical director at Yorkville Endoscopy, where Rivers was having her procedure and went into cardiac arrest, was asked by the board to step down from his post and accepted, "The Insider With Yahoo" confirmed on Friday.

"Dr. Cohen is not currently performing procedures at Yorkville Endoscopy; nor is he currently serving as medical director," a spokesperson for Yorkville Endoscopy said.

Despite attempts to revive Rivers once she stopped breathing, she never regained consciousness. She died at Mount Sinai Hospital on Sept. 4 after being removed from life support.