Holes in the Department of Education’s oversight of tutoring companies that work in city schools allowed one of the companies to collect payments without proving it had delivered services, according to an audit by Comptroller John Liu.

Liu found that Champion Learning Center collected about $860,000 in the 2009-2010 school year for tutoring students who had not signed into tutoring sessions or for tutoring sessions that officials had not certified had taken place.

The audit highlights the murky world of “supplemental educational services” providers, companies that offer tutoring mandated under the No Child Left Behind law. They are private entities but are subject to a host of city and state regulations, and the city must both monitor them and give them access to students.

The audit comes weeks after the U.S. Department of Justice filed suit against another SES provider, Princeton Review, for falsifying attendance records and bilking New York City out of millions of dollars. In that case, investigators found that the company had submitted false signatures showing that tutoring sessions had taken place.

Liu does not conclude that outright fraud took place at Champion Learning, which New York Daily News columnist Juan Gonzalez revealed three years ago took home as much as $320 an hour for serving city students when overhead costs were included. Rather, Liu found that the group violated some regulations by delivering tutoring during school hours and played fast and loose with others — and that the city’s monitoring systems allowed for the possibility of fraud.

Liu wants the city to try to recoup the irregular payments to Champion Learning, and city officials said they would heed the suggestion.

“While the law requires that we offer contracts to all state-approved providers, they still have to comply with their contracts and applicable regulations,” said Marge Feinberg, a department spokeswoman, in a statement. “We will seek to recoup all payments for services that were not permitted or that could not be verified.”

Liu’s office has also referred the audit to the city’s Special Commission of Investigation for further scrutiny. SCI has previously detailed improprieties by other SES providers in the city.

Liu’s audit of Champion Education Partners is below.