The owner of a Long Island special-education company misused millions of dollars in public money, employing 11 family members, leasing Cadillacs, and paying a son’s living expenses in California, then fabricating documents to cover his tracks, the state comptroller’s office claimed in an audit.

The audit, which is being issued on Thursday, is the latest to examine the $2 billion preschool special-education program, which relies on contractors to deliver services to more than 60,000 children in the state between 3 and 5 years old who have physical, learning, developmental and other disabilities.

The company, IncludEd Educational Services of Cedarhurst, closed in April, after a reduction in its tuition rate, retroactive to the 2005-6 school year, left it owing the New York City Education Department $3.15 million, officials said on Tuesday.

The state comptroller’s audit found an additional $2.6 million in overbilling from 2007 to 2009.

“Waste, fraud and abuse cannot be tolerated in our special-education programs, but my auditors keep finding it,” the comptroller, Thomas P. DiNapoli, said in a statement. “The state and localities need to improve their management and oversight of special-education providers.”