Joan Rivers entered the Yorkville Endoscopy Clinic in Manhattan to undergo a routine operation on Aug. 28. A week later she died at Mount Sinai Hospital and the doctor who performed Rivers surgery continues to see patients.

Dr. Gwen Korovin performed a laryngoscopy on Rivers, and the clinic workers claim the doctor took a selfie photo in the procedure room right before the comedian's operation, according to CNN.

Melissa Rivers plans to sue the clinic that the New York Department of Health has under investigation, according to the Daily Mail. Yorkville's medical director Dr. Lawrence Cohen already resigned his post on Sept. 12.

"Melissa does plan to sue the clinic. It's very difficult to discuss something so unpleasant with her, but she is going to launch a lawsuit," a friend of Melissa's told the Daily Mail.

The New York medical examiner has not established an official cause of death, and a toxicology report is still pending. The Rivers family always wants to know if an anesthesiologist was present during the procedure, according to the Daily Mail.

Korovin reportedly was not certified to practice at Yorkville Endoscopy Clinic, and was only to observe Cohen during the procedure, according to CNN. She "categorically denies" the selfie photo reports and the clinic denies a vocal biopsy reportedly conducted on Rivers prior to her going into cardiac arrest.

The health department's investigation includes "examining documents and medical records, observing the facility, and interviewing staff members and doctors to make sure the center is complying with state health regulations," according to NBC News.

Rivers stopped breathing during her procedure and doctors put her on life support when arrived at the hospital. She died on Sept. 4.