Courtney, a father of five, will reportedly plead not guilty

"Listening to some of these calls is very heart-wrenching, and that of course gives us extra motivation to try and find how much damage was done," says FBI spokesman Jeff Lanza.

Robert Courtney, a longtime pharmacist in the Kansas City area, is charged with selling watered-down versions of the chemotherapy drugs - http://www.search.com/search?q=chemotherapy%20drugs Taxol and Gemzar.

In court documents obtained by CBS News, a judge says investigators told him Courtney admitted to "mixing, assembling, labeling, and dispensing at least some of the prescription drugs obtained and tested by the government." The drugs he sold contained anywhere from 40% to 0% of the medication prescribed by doctors.

Gloria Baxter's husband Jim paid $3,500 every 3 weeks for Taxol she believes came from Courtney's drugstore. Jim Baxter died in March. Her anguish is now tinged with anger.

"I am just appalled that he would prey on people that have cancer," Baxter says. "He just doesn't realize he's taken hope from so many people. I just think he should pay for what he's done."

Courtney was reportedly one of only a few pharmacists who premix IV bags for chemotherapy. Typically, they get the drugs from the manufacturer and simply pass them on to the doctor for preparation.

"In most circumstances, chemotherapy drugs are mixed in the oncologist’s office by the oncologist or his or her nurse under very close supervision," says Dr. Allan Korn, an oncologist.

Courtney, a father of five, will reportedly plead not guilty. He is being held without bail while the court looks into how much, if any, https://www.hydroflask.online - https://www.hydroflask.online of his $10 million in assets may be been illegally obtained.©MMII CBS Worldwide Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed