Gastroenterologist who performed Joan Rivers procedure steps down

NEW YORK -- Sources tell ABC News that Dr. Lawrence Cohen allowed a specialist unaffiliated with Yorkville Endoscopy to examine comedian Joan Rivers, even though that doctor was not authorized to practice at the clinic. That ear, nose and throat specialist was present at the time of the endoscopy.

A spokesperson for the clinic confirms that Cohen "is not currently performing procedures at Yorkville Endoscopy; nor is he currently serving as medical director."

Yorkville Endoscopy denies that a vocal cord biopsy was performed as stated in some reports, but the clinic does not deny that rivers had an unplanned procedure. About 18,000 procedures have been performed at the clinic since the center opened in February 2013.

Cohen is a gastroenterologist who recently opened a new office just blocks away on Park Avenue. According to the state Department of Health, he has been licensed to practice since 1979. The department is investigating, but neither Cohen nor the ENT specialist has been accused of wrongdoing.

Rivers was reportedly undergoing a procedure on Aug. 28 to determine the cause of her raspy voice. The clinic would not comment citing patient confidentiality laws.

Cohen has not responded to our requests for comment. Neither he nor the unaffiliated physician have been accused of wrongdoing, but the investigation by the state health department continues.