ATLANTA (AP) _ The FBI has added two more pharmacists to the list of defendants in a nationwide undercover investigation of prescription drug diversion.

John Anthony Marzullo, 41, owner of Physicians' Pharmacy in Austell, was charged Thursday with one count of mail fraud and one count of adulterating and misbranding drugs, said Assistant U.S. Attorney Gale McKenzie.

Richard Alan Pawliger, 42, part owner of Physicians' Pharmacy in Smyrna, was charged with adulterating and misbranding drugs, she said.

Marzullo and Pawliger are accused of removing the word ''sample'' and other packaging information from drugs sold to them by representatives of drug manufacturers. The samples, intended for free distribution, then were sold, court papers charge.

Federal authorities said such action causes a public health risk because the unlabeled drugs may be used past their expiration date and are missing the lot numbers needed to recall tainted pharmaceuticals.

U.S. Attorney Larry Thompson said the sales representatives who sold the drug samples to Marzullo and Pawliger have not been charged. He added, however, that as many as 40 people may be added to the list of 43 individuals and three companies charged in the investigation Tuesday.