CRYSTAL LAKE – The state is investigating the billing practices of a local substance abuse treatment center as a dispute between the center and the McHenry County Mental Health Board heads to federal court.

"After recently receiving information about possible billing irregularities by the Advantage Group, the department conducted an analysis and found instances of possible concern, which were immediately referred to the Office of the Inspector General at the Illinois Department of Healthcare and Family Services for a thorough investigation," said Kayce Ataiyero, a spokeswoman for the state's Department of Human Services.

The Advantage Group Foundation, a nonprofit organization in Crystal Lake, filed a complaint in U.S. District Court in Rockford last week seeking to block the county’s taxpayer-funded mental health board from trying to recoup nearly $1.1 million in payments for disputed services.