Gwen Korovin, an esteemed New York ear, nose and throat doctor, is reportedly the physician who performed Joan Rivers’ unauthorized biopsy at Yorkville Endoscopy that led to her unexpected death.

Did Gwen Korovin Peform Joan Rivers' Biopsy?

Korovin has been identified as Rivers’ personal doctor and the one who was operating on her when she stopped breathing, reported TMZ. She was not authorized to practice medicine at Yorkville Endoscopy. Incidentally, it’s also believed that she is the doctor who decided to take a selfie of herself with the unconscious comedian prior to performing the ill-fated procedure.

Korovin is known as the ENT of the stars, particularly those on Broadway, claiming to specialize in “voice and throat problems” on her Facebook page. Among her high-profile clients are Celine Dion, Hugh Jackman, Lady Gaga, Nathan Lane, John Mayer, Danielle Radcliffe, Ariana Grande and others. Patti Lupon, who also was treated by Kovovin, called her “the patron saint of Broadway actors and singers,” in an interview with the New York Daily News.

Now that it has come to light that Korovin was likely the doctor who performed the unauthorized biopsy that caused Rivers’ vocal cords to swell, blocking her windpipe, sources have said that Joan Rivers' daughter Melissa Rivers is intent on taking action against her.

“Everyone close to Joan thinks Dr. Korovin skipped town,” an insider told RadarOnline. “Joan’s daughter Melissa has been telling friends that she is a spineless monster.”

“Melissa is taking this very seriously,” the insider added. “She has been shocked by the reports of her mother’s ear, nose and throat doctor took a selfie picture with Joan when she was on the table. It only proves to Melissa that she needs to make sure this doesn’t happen to another person. Filing the medical board complaint against Dr. Lawrence Cohen and Dr. Korovin will give Melissa the power to make sure she gets answers.”

When asked for comment, Korovin’s office said, “We’re not commenting at this time due to the professional duty we have to our patients,” according to the Daily Mail.

Joan Rivers died on Sept.4, eight days after she suffered respiratory and cardiac arrest following what was supposed to be a routine endoscopy.