ST. LOUIS -- An eastern Missouri doctor was sued in federal court Thursday on allegations he prescribed powerful drugs that contributed to eight patients' deaths.

The lawsuit seeks to fine Dr. Seth Paskon of Potosi and to limit his ability to prescribe drugs.

Federal prosecutor Catherine Hanaway said coroners' reports showed high levels of prescription drugs contributed to the patients' deaths. Seven of the patients were poor and insured by Medicaid.

Hanaway spokeswoman Jan Diltz would not say if a criminal investigation is underway.

Hanaway said Paskon also provided large amounts of pain and anxiety relief drugs to a visibly pregnant patient. The drugs are not usually prescribed for pregnant women, and both the mother and baby had high levels of those drugs in their blood at the time of delivery.

A woman who answered Paskon's phone said he had no comment on the suit.

Paskon, who received his medical training in Thailand, had been under scrutiny by state regulators for his medical practices, the lawsuit said. He was ordered to take a refresher course in pharmacology and agreed to stop prescribing controlled substances for a time in the late 1990s.

In 2002, the Missouri State Board of Registration for the Healing Arts sought to discipline him for alleged medical misconduct. In March of this year, a commission found no cause to discipline his medical license.