LOS ANGELES (AP) — An operator of sleep study facilities in California has been sentenced to more than two years in prison and ordered to pay nearly $3 million in restitution, authorities announced Monday.

Nick Nikbakht pleaded guilty in December 2016 to a scheme to defraud healthcare plans, according to a news release from the U.S. Department of Labor. He and two other operators have been sentenced in the case.

Nikbakht, Shawn Chait and Oganes Doganyan defrauded multiple health plans by recruiting people to undergo medically unnecessary sleep and nerve-conduction velocity tests in Sherman Oaks and San Pedro. Patients sometimes received $300 to $500 for each sleep study.

The trio submitted at least $16 million in claims to the patients’ health plans, which paid out at least $3 million, the release stated.

Nikbakht and Doganyan additionally transferred proceeds of the funds into other accounts that they controlled and paid the patients. They also sent money to companies controlled by Doganyan so the money would appear to have a legitimate business purpose.

Chait was sentenced to a year in prison and ordered to pay more than $3 million in restitution, while Doganyan was sentenced to 33 months in prison and has to pay $1.4 million.

Attorneys for the trio who could speak on their behalf could not immediately be determined.