Listen to TMZ Report on iHeartRadio

TMZ Report

(NEWSER)– What was supposed to be a routine procedure ended up causing the death of Joan Rivers, a medical source tells the New York Daily News.

According to the source, a doctor in the star's entourage performed an unplanned biopsy after she went in for routine surgery on her vocal cords. The source says Rivers' air supply was cut off when her vocal cords seized up during the unplanned procedure at the Yorkville Endoscopy clinic in New York City. She died a week later. "A biopsy like that should only be done in a hospital setting," the source says. "If she had been in a hospital when it happened, she might have been OK."

Last week, it emerged that the clinic is being "reviewed" by state health officials.

Photo: Getty Images 

Read the full story on Newser.com