COLUMBIA, Mo. (AP) _ A former oncologist who recently surrendered his license and paid a $1 million fine stemming from accusations of Medicare fraud is now the focus of a class-action lawsuit. The lawsuit, filed last week in Boone County Circuit Court, accuses James Hueser and 22 physicians of shortchanging patients by administering diluted or tainted chemotherapy drugs and charging full price.

The legal action was filed on behalf of Ron Merchant. Hueser treated Merchant's wife, Artie Jean Merchant, who died in 2003 of non-Hodgkin's lymphoma, said Tony DeWitt, an attorney with the Jefferson City law firm handling the case.

In a class action lawsuit, any former patient who received treatment from any of the defendants and didn't get what he or she paid for can be part of the settlement or judgment, DeWitt said.

The lawsuit seeks compensatory damages for overbillings and punitive damages to ``deter future wrongful conduct'' by the defendants. The lawsuit also alleges fraud, breach of contract and civil conspiracy.

Hueser could not be reached for comment.

The list of defendants includes an affiliated company, Medical Network Technologies LLC, and former associates of Hueser in the Boone Clinic medical partnership.

But Columbia attorney David Knight, who represents Medical Network Technologies and two doctors in the partnership, said linking Hueser with the other named physicians is ``trolling'' for defendants.

``It's just a hell of a stretch on their part,'' he said. ``From our standpoint, there's no partnership or anything else they allege.''

The U.S. Department of Health and Human Services launched an investigation into Hueser's medical practice in late 2001 after nurses in Kirksville reported that opened vials of chemotherapy drugs were stored for later use, contrary to manufacturer directions and prescribing guidelines.

The investigation revealed that between at least February 1999 and December 2001, Hueser ``routinely billed Medicare for larger doses than were actually given to the patients,'' according to an affidavit filed by investigator Daniel Coney.

In November, Hueser and federal officials reached a settlement in connection with the overbilling of Medicare patients.

Hueser did not admit wrongdoing under the terms of the agreement reached with the U.S. attorney's office in Kansas City.

Hueser, who was based at Boone Clinic, also practiced at Bothwell Regional Health Center in Sedalia and had ``traveling oncology units'' in Hermann, Hannibal and Kirksville.