The probe into Joan Rivers’ death may lead to charges against two doctors, The National ENQUIRER has learned exclusively.

Vincent Parco, a former chief investigator for New York’s Office of Professional Medical Conduct, told The ENQUIRER if the allegations a doctor performed an unauthorized biopsy on the 81-year-old star are true, that physician “could face felony charges and up to three years in jail.”

Parco, who is not involved in the probe, added that a physician who allowed the doctor to perform the biopsy could face “aiding and abetting” charges.

Rivers died Sept. 4 – a week after an alleged throat procedure at Manhattan’s Yorkville Endoscopy.

Dr. Gwen Korovin was named as the doctor who allegedly performed the vocal cord biopsy on Rivers before she suffered respiratory and cardiac arrest.

While Dr. Korovin has denied performing a biopsy on Rivers, reports said she was not authorized to practice at the clinic, which also denies that a vocal cord biopsy has ever been done there.

Dr. Lawrence Cohen was named as the physician who allegedly permitted and oversaw the procedure.

Dr. Korovin also denied taking a photo with Rivers during the operation. Dr. Cohen has since resigned, but neither he nor Dr. Korovin have been accused of any wrongdoing.