Thousands of mental health patients in New Mexico remain unserved as federal authorities continue a two-month investigation into Medicaid fraud involving 15 service providers accused of colluding on $36 million of theft.

An external auditor last year discovered systemic fraud within the state’s Medicaid system, compelling Gov. Susana Martinez’s administration to hire Public Consulting Group, of Boston, to further investigate. The state subsequently halted Medicaid payments to the service providers, who deny wrongdoing. Martinez is currently facing a political backlash for the investigation from some state lawmakers and the non-profit group New Mexicans Fighting For Behavioral Health, which has run radio ads lambasting the administration.

State officials say that in addition to over-paying $36 million to healthcare agencies, as many as one-quarter of all claims were processed with mistakes. Gov. Martinez cited a provision of the Affordable Care Act of 2010 requiring states to halt payments in such cases to fight fraud in the Medicaid system, in addition to pressure from U.S. Congressmen to stem fraudulent payments.

“When we saw the totality of it all, it was extremely sobering,” Diana McWilliams, chief executive of the state's behavioral health system, told The New York Times. “We had to look at our entire system, and that’s what we’re doing. It’s scary, but it’s necessary.” McWilliams added that auditors had found a “suspicious business arrangement” among a group of mental health service providers apparently transferring Medicaid money from agencies to corporation executives. “I’m stunned at some of the business practices that have been going on,” she told The Times.

For their part, executives of the mental health service providers in question have reacted to the investigation with surprise and mystification. “We were all just shocked,” Patsy Romero, the chief operations officer for service provider Easter Seals El Mirador, told The Times. “Before this, we have never received any type of audit or call to tell us there was anything wrong.”

Democratic legislators took the opportunity to criticize the Republican governor at a hearing in Las Cruces, asserting that providers should be given a chance to defend themselves before losing Medicaid funding, given that even a temporary suspension of payments might drive some providers from the business.

“You need accountability in the system of care,” Ms. Romero said. “But you have to have a dialogue back and forth with the providers.”

Meanwhile, mental health patients such as Michael Bruening, a 12-year-old with autism spectrum disorder, go without treatment as funding remains frozen at his provider in Albuquerque, his mother Laura told The Times. “I’m really concerned that we don’t have anybody to intervene if something happens with him at school,” she said.

A federal judge in Albuquerque in July dismissed a challenge from some of the providers to reinstate funding as the federal fraud investigation continues.

Below is a YouTube video containing a radio ad from New Mexicans For Behavioral Health: