The federal No Child Left Behind program was supposed to provide money to hire private tutors for students in troubled school districts, but funding has disappeared in recent years.

Part of the decade-old program provided billions of dollars in aid to hire private tutors for underprivileged students. Locally, only the Central Islip School District still benefits from the program, which virtually collapsed two years ago amid a flood of controversy and allegations.

A Newsday/News 12 Long Island investigation found that the program provided money to at least 15 tutoring firms with histories of significant problems.

Owners of one of the tutoring firms, Babbage Net, were indicted last year for allegedly defrauding school districts in 19 states. Yet despite the charges, the government website still lists Babbage Net as an approved tutoring provider.

Another company, the Champion Learning Center, was criticized in a 2012 New York City audit for collecting $1 million in "questionable payments" when the company couldn't show proof students had attended late-night study sessions.

News 12 was unable to reach Babbage Net or Champion Learning officials for comment.

Former Comptroller John Liu says the government should warn parents about firms with such problems.

In Central Islip, Eric Stanley gets math tutoring through the program. His mother, Sonya Stanley, says it's the only way he could catch up in class.

"There was no other way he would be able to be tutored," she says. "I couldn't afford tutoring for my child at all."

However, critics say children in other families that cannot afford tutoring on their own may never see similar help due to greed and lax oversight. They say that if the government had kept a closer eye on the questionable firms, No Child Left Behind might not have collapsed.

Tune in tomorrow at 5 p.m. for the final part of the Private Lessons series, which will look at whether tutoring has widened the inequality gap between wealthy and underprivileged students on Long Island.