FORT WORTH, Texas (AP) — A North Texas fitness guru has been charged with submitting over $25 million in fraudulent claims to insurance companies.

David Williams of Fort Worth is free on bond after his Thursday arrest.

A criminal complaint alleges that between November 2012 and this past August, the 54-year-old trainer was paid more than $3.9 million through fraudulent billing of United HealthCare, Aetna and Cigna.

Williams advertised on the internet offering in-home fitness training and therapy. A Justice Department statement Friday states that 54-year-old fitness trainer falsely certified that he was a health care provider and billed for medical services.

Williams' attorney, Wes Ball of Arlington, says his client believed he was acting legally until that legality was questioned and he stopped.

If convicted, Williams can be sentenced to 10 years in prison.