A CNN Investigation into fraudulent drug rehabilitation clinics concluded that the populous Los Angeles region is one of the nation’s top hot spots for health care fraud, and former state officials agree it is also ground zero for the rehab racket. To uncover this story on widespread fraud linked to California’s drug rehab program, CNN’s Special Investigations Unit has teamed up with the independent, nonprofit Center for Investigative Reporting as part of Anderson Cooper AC360’s “Keeping them Honest” reports.

Investigative reporters were were stationed in parked cars outside the offices of Able Family Support in the San Fernando Valley, counting the people who came and went on April 4. The clinic, reimbursed by taxpayers for each client it sees, offers in-person drug and alcohol counseling. And Able Family is thriving, according to its billing records.

But according to the reporters, no more than 30 people trickle into the rehab center on April 4 until the doors are locked 10 hours later.

The counting resumed a month later when the clinic submitted its bill to Los Angeles County seeking reimbursement — not for 30 people, but for 179. The government promptly paid it — $6,400 for clients Able Family reported it saw April 4. When told of the April 4 stakeout at Able Family, county regulators said they now have questions about whether the payments were legitimate. The findings merit a closer review but “look very incriminating,” said a spokeswoman for Los Angeles County’s substance abuse department. Able Family operates a small satellite clinic near downtown, the county noted — but a security guard there said about 25 people came to that office each day.

The simple stakeout on April 4 raises questions about the adequacy of government oversight of the program to help the poor and addicted, built on an honor system in which honor often is lacking. Oversight is marred by infrequent and cursory inspections and by a failure to act even when red flags appear. CIR and CNN have exposed how clinics use coercion and forgery to defraud a taxpayer-funded program meant to help struggling addicts..The investigation also found that people ineligible to run Medi-Cal clinics did not just slip through the cracks — they walked through doors regulators left wide open.

The Able Family Support Clinic’s director, Alexander Ferdman, would not explain the discrepancy. “I can’t explain, because you will cut and paste and edit, and my answers will be to a totally different question,” Ferdman said in a telephone interview, before hanging up. Felons are supposed to be blocked from running clinics. That didn’t stop Ferdman. He entered the rehab racket two years after leaving a Texas prison, where he served time for orchestrating an organized crime scam. Over the course of a decade, he built his clinic into a $2 million-a-year operation — all from taxpayer money. Prosecutors in Texas had pegged Ferdman as the ringleader of a scam that robbed auto insurers of millions. An indictment from the Travis County district attorney’s office says a team of fixers staged crashes and recruited actual crash victims as pawns to generate fake legal and medical bills. One witness described Ferdman as the man who paid off operatives from a briefcase full of cash.

CNN claims that Drug Medi-Cal paid out $94 million in the past two fiscal years to 56 clinics in Southern California that have shown signs of deception or questionable billing practices, representing half of all public funding to the program, CIR and CNN found. Over the past six years, more than half a billion dollars have poured into the program statewide.