A doctor and two office managers at Ohio pain clinics have been accused in a federal indictment of illegally distributing the powerful painkiller OxyContin and other drugs that led to the deaths of at least 14 people, federal prosecutors said Tuesday.

Dr. Paul Volkman, 60, was arrested Monday in Chicago, where he has a home, said Fred Alverson, a spokesman with the U.S. Attorney's Office in Columbus.

Volkman worked out of southern Ohio clinics in Portsmouth and South Point, where he and two office managers distributed more than 1.5 million pain pills between 2001 and 2006, prosecutors said.

A federal grand jury in Cincinnati returned a 22-count indictment against Volkman and office managers Denise Huffman, 54, and her daughter, Alice Huffman Ball, 32, both of Portsmouth.

Each faces numerous charges, the most severe being a charge of distributing a controlled substance that results in death, a felony that carries a maximum penalty of life in prison, Alverson said.

The indictment named the people alleged to have died but didn't say if they lived in Ohio or elsewhere.

James Rion, an attorney for Denise Huffman, denied the allegations.

"They were involved in a legal operation," he said. "Drugs were dispensed in a lawful manner."