A former Tulsa dentist accused of exposing thousands of patients to hepatitis and HIV now faces a federal charge.

The United States Attorney's Office for the Eastern District of Oklahoma announced Tuesday that it charged Wayne Scott Harrington, 67, with money laundering. 

Prosecutors say Harrington laundered money obtained from fraudulent billing of Medicaid and Medicare while he was a dentist. They say the charge is a result of an investigation by the FBI, the IRS, the Department of Defense, the Department of Human Services, the DEA and the Oklahoma Attorney General's Office.

Harrington surrendered his license in August of 2014 amid allegations that he ran unsanitary clinics in Tulsa and Owasso. His clinics had closed in March of 2013.

The Tulsa Health Department and other health departments across the state provided free screenings for patients of Harrington. Of the more 4,000 people tested, 77 patients tested positive for hepatitis C, five for hepatitis B. Three tested positive for HIV.

Health officials have not confirmed that any of those cases were contracted at Harrington's practice.

A number of his former patients joined a class action lawsuit against him.