SANTA ANA, Calif. (AP) — A Beverly Hills, California, surgeon and his girlfriend have pleaded not guilty to taking part in a $52 million insurance fraud scheme that involved recruiting patients at Southern California sober living homes to undergo unnecessary surgeries and other procedures, prosecutors said Friday.

Dr. Randy Rosen and Liza Visamanos, both of Los Angeles, entered pleas Thursday in Orange County to a total of nearly 150 felony charges, the county district attorney’s office said in a statement.

Four other people also have been charged in connection with the alleged scheme.

Prosecutors said they hired “body brokers” to find and pay sober living facility patients to have unnecessary tests, cortisone shots and implants of Naltrexone, a drug that can reduce cravings for opioids and alchohol.

Insurance companies were then billed for the procedures, authorities said.

“Vulnerable sober living patients who were trying desperately to battle their addictions were treated like human guinea pigs just to make a buck,” District Attorney Todd Spitzer said, calling the defendants “real-life Frankensteins.”

If convicted of all charges, Rosen could face decades in state prison.