ALBANY -- State auditors say a central New York agency caring for the mentally disabled made more than $1 million in purchases through improper collusion with vendors and bid rigging.

New York State Comptroller Thomas DiNapoli says he has turned over the audit of the Central New York Developmental Disabilities Services Office to the Oneida County District Attorney's office.

DiNapoli says in some cases the state paid at least 40 percent more for work done at group homes than it should have. DiNapoli says the scheme went back as far as 2003.

Two previous state audits in 2007 also turned up questionable practices by the DDSO, which provides care for about 4,000 individuals in eight upstate counties.

DDSO officials did not immediately return a phone call seeking comment.