Real Cause of Joan Rivers' death will remain a mystery since daughter Melissa NEVER ordered autopsy

The world will never know what action killed Joan Rivers' after a routine surgery, because her heartbroken daughter told doctors NOT to perform an autopsy.

The comedian died last month after a throat surgery left her brain dead.

Daughter Melissa Rivers was left so despondent by her mother's sudden and unexpected passing that she specifically requested no autopsy be conducted, TMZ reports. 

According to New York law, a family member can request that if there's no evidence of criminality associated with the death.

Rivers died from a 'predictable' complication involved in the throat procedure, the New York Medical Examiner reported. 

A further autopsy could have pinpointed what exactly what went wrong during the surgery - such as a puncture in the throat or some other trauma.  

Yorkville Endoscopy, the clinic where Rivers underwent surgery, has since been deemed deficient in four major categories required for accreditation following an investigation by the New York State Health Department. If it does not correct these problems, it will lose its license on January 7 of next year. 

In a October 9 letter to the clinic's director of operations, Tricia Dougherty, obtained by MailOnline, the categories the clinic is 'noncompliant in the following four areas:  'governing body and management, surgical services, medical staff and patient rights.'

'This is a big, big deal,' Dr. Jerome Waye, a Manhattan gastroenterologist who has spoken with physicians on the Yorkville staff about the investigation, told MailOnline. 

'They won't be able to take Medicare patients, and that's got to be at least half their clientele.'

'I don't know of any circumstance where the whole Medicare certification is pulled over one doctor doing one procedure,' said Waye.

'I'm quite surprised that Medicare has come down on Yorkville like this,' Waye said.

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TMZ reports that Melissa was so heartbroken in the wake of her mother's sudden passing that she did not want the autopsy performed. Pictured at her mother's memorial service above 

Shut down: Yorkville Endoscopy (above) has until January to fix their problems or they will lose their license. Dr. Lawrence Cohen, who was director of the clinic and Joan's gastroenterologist was forced to step down

Waye said it appeared as though the violations were directly related to the Rivers incident.

Dr Wayne believes that the violation of patient's rights cited alludes toThe patient's letting someone not certified do the biopsy, violating [Rivers'] rights and and the 'governing body and management' I for them not following protocol in letting the doctor do the unauthorized procedure,

After reading the letter, Dr.Wayne believes that that 'they didn't do much of an investigation, if they didn't find any wrongdoing by the doctors. It looks like they just threw everything they could at [Yorkville], saying you had all these violations, now we're going to take away your certification.'

Other specifics are not being disclosed at this time.

Deficient: The clinic where Joan Rivers went into cardiac arrest while undergoing routine surgery has been deemed 'deficient' by the New York State Health Department

Furthermore, the Centers for Medicare and Medicaid Service notified the clinic that it 'no longer meets the requirements for participation as a supplier of services in the Medicare program.'

A source close to the investigation confirmed to the MailOnline that Yorkville did, indeed, respond to the Oct. 9th letter with a Plan of Correction within the ten days required by Medicare. 

The source also confirmed that the investigation resulted from a complaint over the Rivers' incident.

This news comes just one day after it was revealed that Rivers died due to a lack of oxygen in her blood.

The popular comedian was having routine surgery at Yorkville Endoscopy on August 28. Her gastroenterologist, Dr. Lawrence Cohen, who was in charge of the procedure, has since left the practice. Joan's throat specialist, Dr. Gwen Korovin, was also in the room, when she went into cardiac arrest.

On hand: Dr. Gwen Korovin (above), Rivers' throat specialist, was one of the people in the room when the comedian went into cardiac arrest 

'I've had an amazing life': Joan Rivers gets serious (archive)

She was then rushed to Mount Sinai Hospital where she was put into a medically induced coma and then on life support before passing away at the age of 81 on September 4.

Following yesterday's news Rivers' daughter Melissa released a statement saying, 'We continue to be saddened by our tragic loss and grateful for the enormous outpouring of love and support from around the world.'

The Center for Medicare & Medicaid Services (CMS) spokeswoman Courtney Jenkins, who provided the letter in response to a request about the Rivers investigation, was not immediately available to comment on the letter. Maya Voynarovska, a spokeswoman for Yorkville Endoscopy, was also not immediately available to comment on the letter.