PHOENIX -- A Valley physician already on probation is now suspended and the state medical board says his patients may be in danger.

The Arizona Medical Board said it received an anonymous complaint that Dr. Marvin Gibbs was practicing medicine while his license was suspended.

Gibbs is board-certified in obstetrics and gynecology.

VIDEO: Watch 5 Investigates Report From Sept. 2004

Board staff said they were able to confirm that Gibbs was practicing medicine and that one of his patients was harmed by his treatment, ending up in the emergency room.

The patient received his refill from one of Dr. Gibbs' employees in the parking lot at 7th Street and McDowell in Phoenix, according to a board statement.

The Board said it strongly advises that anyone who may have received prescription refills from Gibbs at his office or in that central Phoenix parking lot not to take the medication and to see a physician.

Gibbs' license was suspended last August after the board determined that he represented a danger to the public for a treatment of a male patient with sexual dysfunction.

CBS 5 News has been on the trail of Gibbs since 2004 when our investigation publicly exposed his first run-in with the state medical board.

At that time, he was slapped with a $10,000 fine for prescribing dangerous narcotic painkillers to people over the Internet.

Since then, he's been in trouble three times with the state board -- for providing false information to hospitals, violating his probation and mostly recently for practicing without a license and putting patients at risk.