NEW YORK (WABC) -- Melissa Rivers has hired a lawyer to investigate the death of her mother, legendary comedienne Joan Rivers.
In a statement, Ben Rubinowitz said his law firm will work to determine the facts and circumstances surrounding the death.
He denied reports that a lawsuit is planned.
Rivers died in early September after suffering cardiac arrest during a medical procedure.
The New York City Medical Examiner released its report Oct. 15 on the investigation into the cause of death for Rivers, concluding that she died from low blood oxygen during the procedure.
The report said the death was caused by "anoxic encephalopathy due to hypoxic arrest during laryngoscopy and upper gastrointestinal endoscopy with propofol sedation for evaluation of voice changes and gastroesophageal reflux disease."
The report said the manner of death is therapeutic complication.
The finding was that Rivers was sedated with propofol before she died of low blood oxygen during a procedure to treat voice changes and acid reflux.
Anoxic encephalopathy means that she did not have sufficient oxygen to her brain tissue for a prolonged period of time, which caused damage to her brain.
Rivers, who was 81, died a week after going into cardiac arrest at an Upper East Side clinic. She was undergoing a routine diagnostic procedure to examine raspiness in her voice and reflux, and was under anesthesia.
Joan Rivers' daughter Melissa hires lawyer to investigate death