Joan Rivers' daughter is suing Yorksville Endoscopy clinic for medical malpractice.

In a statement, she said: "The level of medical mismanagement, incompetency, disrespect and outrageous behaviour is shocking and frankly, almost incomprehensible."

Joan’s personal doctor, Gwen S. Korovin, has been accused of performing two unplanned biopsies on the former 'Fashion Police' star.

According to the papers, Gwen, the head of the Yorksville Endoscopy medical clinic, Dr. Lawrence Cohen, an anaesthesiologist named Renuka Bankulla and others "failed to properly observe and monitor Joan Rivers’ vital signs which were deteriorating."

The lawsuit continues to state that Renuka had "voiced her concern about the presence of airway edema and the possibility of airway compromise with further manipulation" but was told by Lawrence not to be "paranoid".

Lawrence then allegedly made a joke, telling Renuka, "You’re such a curious cat. You always want to know what’s going on" when she asked to use a mirror to see Joan's vocal chords.

The papers then state that he took out his phone and snapped a picture of Joan whilst she was sedated, apparently telling those in the room, "Maybe Joan Rivers will like to see these in the recovery area."

At around 9:28 am, the suit states that Joan's heart rate slowed and her oxygen dropped below 90 per cent, with the anaesthesiologist reportedly struggling with an oxygen mask and failing "to demand or request a crash cart be brought into the room".

Papers submitted to the court accused Renuka of "waiting minutes"

before asking for help. An emergency tracheotomy kit was ordered but the procedure was never performed, the suit continues.

The suit specified that a 911 call was made at 9:40 am but that was 12 minutes after an emergency warning, "blue code", was first given.

Gwen then reportedly fled the building, with the lawsuit alleging that she did this because she wanted to "avoid getting caught".

"By leaving the procedure room, [she] abandoned her patient, Joan Rivers,” the suit continues.

A falsified patient chart that failed to mention the two procedures done by Gwen was reportedly submitted by Lawrence.

The comedian "suffered hypoventilation, airway obstruction, hypoxemia and severe and prolonged hypoxia which caused cerebral anoxia and eventual death", according to the papers.

Melissa Rivers and the ex ecutors of Joan's estate have filed the suit against Yorkville Endoscopy, the parent company Frontier Healthcare and gastroenterologist Lawrence Cohen as well as Joan’s personal doctor, Gwen Koravin, and the three anesthesiologists involved in the throat procedure.

They are seeking unspecified compensatory and punitive damages.