SACRAMENTO — State Sen. Mimi Walters, an Orange County Republican, landed at the center of an ethics investigation after she helped a firm owned by her husband collect cash from the state prison system.

Now at least a dozen subcontractors — dentists and pharmacists hired by two of David Walters’ companies to treat inmates — say the firms owe them more than $120,000 in back payments.

The workers have filed complaints in court and with the state labor commissioner. Some are demanding Sen. Walters step in to make sure they get paid.

David Walters is a co-owner of American Healthcare Recruiting, as well as Drug Consultants Inc. — two firms that have contracts with the state to provide medical workers for the California Department of Corrections and Rehabilitation.

The Times recently reported that the state Fair Political Practices Commission was investigating whether Sen. Walters violated conflict-of-interest rules when her office repeatedly called prison officials to check on a claim filed by Drug Consultants Inc.

The state in February paid the company a $74,400 settlement.

An aide to Sen. Walters “called CDCR to help get money for her husband,” said dentist Jack C. Luomanen. “But they haven’t passed that money to the people they owe.”

Luomanen said American Healthcare Recruiting owed him $13,700 for care he provided to inmates at Solano State Prison and Central California Women’s Facility in November, December and January.

“It’s caused a huge problem in my life,” he said. “I’ve had to take money out of savings to pay expenses. I’ve never been treated so poorly in my life.” Luomanen is suing the company in small claims court and said he planned to file a complaint with the state labor commissioner.

Burton Norris, a Chula Vista dentist, said he was owed $17,160 for work done through American Healthcare Recruiting. Last month, he wrote a letter to the senator, asking her to intervene for him as she did for her husband.

“I read that you stand for fiscal responsibility on your web site and I do expect you to make sure that your husband’s company does the same,” Norris wrote.

Dentist Keith Kawalski has filed a complaint with the state Division of Labor Standards Enforcement seeking help in recovering the $16,000 he said he was owed. A formal hearing is pending.

Nancy Kincaid, a spokeswoman for the corrections department’s health division, said both companies had been paid for all the work done during the period in question.

Sen. Walters has referred the letters she received from medical workers to her husband’s businesses for response, according to Charles Bell, her attorney.

The two firms are wholly owned subsidiaries of Monarch Staffing Inc., in which David Walters has a 40% interest. The issue, Bell said, “appears to be a private dispute between several individuals and the private company in which Sen. Walters’ husband has an interest.”

Although the lawmaker has a financial stake in her husband’s business by virtue of the state’s community property laws, Bell said she has “no role whatsoever in that company,” and “no knowledge of the company’s handling of this matter.”

Larry Drechsler, a pharmacist who said he was owed $4,900 for work he did in 2011, has filed suit in small claims court. “To spend a month away from your family so you can work at a prison and then not get paid? It’s bad,” he said.

patrick.mcgreevy@latimes.com