As the investigation of Joan Rivers' death continues, reports of disturbing alleged details continue to surface.

While Rivers was under anesthesia at Manhattan's Yorkville Endoscopy on August 29 and her personal doctor -- an ear, nose and throat specialist -- started to conduct a procedure on her vocal cords, staff at the outpatient clinic claim the doctor took a selfie with Rivers in the background, CNN reported.

In addition, staff at the clinic reportedly told authorities Rivers' ENT, although a licensed physician, executed an unauthorized procedure -- widely reported to be a biopsy -- and was not certified to operate there. No signed consent form was allegedly found from Rivers, agreeing to a potential biopsy.

When questioned whether Rivers' personal doctor allegedly took a selfie while the comedian was under anesthesia, a representative for Yorkville Endoscopy told People the following: "Yorkville has said and still says that a biopsy of the vocal cords was never attempted or done at its site ever. HIPAA [Health Insurance Portability and Accountability Act] laws prevent us from disclosing any information about patients or their procedures."

Rivers reportedly entered Yorkville Endoscopy for a scheduled endoscopy by its gastroenterologist Dr. Lawrence Cohen in which a tiny camera was inserted down her throat, looking for possible digestive issues. After Cohen found something, Rivers' personal doctor examined the comedian's vocal cords and allegedly began a biopsy.

Staff at the clinic claim Rivers' vocal cords swelled during the biopsy, cutting off her oxygen and putting her into cardiac arrest. Ten emergency personnel eventually arrived at the scene and she was taken to Mount Sinai hospital, where she died one week later.

Yorkville Endoscopy appeared to dodge the selfie topic while continuing to insist a biopsy was never completed or even attempted on Rivers at the clinic despite multiple sources and reports alleging otherwise.

Ironically, the outpatient clinic had released another statement recently saying Dr. Cohen "is not currently performing procedures at Yorkville Endoscopy; nor is he currently serving as medical director," CNN reported.

Rivers died at the age of 81 after her daughter Melissa Rivers reportedly took her off life support. She had starred in Joan & Melissa: Joan Knows Best and also won The Celebrity Apprentice's second season.