The New York Medical Examiner’s office has finally determined Joan Rivers’ cause of death. It was announced on Thursday that the comedy legend died of anoxic encephalopathy caused by hypoxic arrest (a lack of oxygen to the brain). No word as of yet on whether Rivers’ death could have been prevented. There has been talk, since the star’s medical decline began, that her daughter Melissa might be considering a lawsuit. This latest development may strongly inform that decision.

Rivers made headlines worldwide when she was rushed to the hospital in late August, after suffering a cardiac arrest during elective throat surgery. She was put in a medically induced coma, and then kept on life support of one week, before doctors pulled the plug on September 4. Gossip Cop now reports that the 81-year-old was sedated using Propofol, when she stopped breathing, possibly during an unauthorized biopsy.

Propofol, a high-grade sedative, has been linked to another very high profile celebrity death in the past – that of Michael Jackson. In 2009, the pop legend also died of a cardiac arrest, caused by a toxic mix of the drug with benzodiazepines. It was discovered that Dr. Murray Conrad had given Jackson a prescription for the intravenously administered substance, despite the fact that it is only supposed to be used in a hospital setting. Murray was convicted of involuntary manslaughter in 2011, and served two years in prison.

The circumstances surrounding Rivers’ death were completely different, but there have been reports of possible wrong doings by the doctors who performed her procedure. Dr. Gwen Korovin, Rivers’ ear nose and throat specialist was accused of not only allowing the alleged unauthorized biopsy, but also stopping the procedure at one point to take a selfie with the unconscious star. Korovin denied that either the biopsy or the selfie took place, and TMZ reported that many of her other celebrity clients rushed to her defense. What ever actually happened; Dr. Lawrence Cohen, the surgeon who was operating on Rivers, was fired from the Yorkville endoscopy clinic.