Joan Rivers Death Lawsuit: Yorkville Endoscopy Believed Comedian's E.N.T. Was Her Makeup Artist? [VIDEO]

The Yorkville Endoscopy Center allegedly thought Joan Rivers' Ear Nose and Throat doctor was her makeup artist.

Joan Rivers' Unauthorized Throat Biopsy a 'Big No-No,' Source Said

While the cause of death remains unknown, a new report alleges the center, in which Rivers underwent the procedure that ultimately killed her, was in the dark about one of the members of her team.

On Sept. 12, Radar Online reported the E.N.T. was wrongfully identified as an observer, not a doctor, and was carrying a bag whose contents were unknown. This led some to believe she was on-hand to "make [Rivers] look her best" post-procedure.

Joan Rivers: Clinic Says 'Biopsy of The Vocal Cords Has Never Been Performed'

Regardless, reports say the individual was not authorized to practice medicine or perform any procedures at Yorkville Endoscopy.

The E.N.T. was brought into the operating room with Rivers' gastroenterologist, Dr. Lawrence Cohen, who is also the clinic's medical director. After specialists examined Rivers' throat, Dr. Cohen performed an upper endoscopy, which "uses a tiny camera to look down a throat in order to see the digestive system," said Radar Online.

Dr. Cohen has since stepped down, TMZ reported today. The board, however, admitted they did not directly blame him for Rivers' death, but they do blame him for allowing the unauthorized individual to perform a throat biopsy in the clinic. Cohen has been on administrative leave since the procedure took place. 

Doctors are not allowed to perform any medical procedures until their credentials are evaluated by medical facilities, according to state and federal regulations. Thus far, reports have said Rivers' E.N.T. and gastroenterologist have not been found guilty of any misconduct.

Still, the New York State Health Department is continuing its investigation.

As previously reported, Rivers suffered cardiac arrest during a routine throat procedure at Yorkville Endoscopy on Aug. 28. She died a week later at New York City's Mount Sinai Hospital. Officials are unsure what the cause of death was, but speculation is that it was either the procedure or the clinic's method of sedation, Propofol, reported Radar Online.