Calls are growing for the U.S. Department of Education to reject the authority of a controversial accreditor to be a gatekeeper for federal student aid.

A study released on Monday by the Center for American Progress found that the Accrediting Council for Independent Colleges and Schools has continued to accredit 17 institutions or companies that are under state or federal investigation, taking little or no action to penalize them. During the past three years, those entities have received about $5.7 billion in federal student aid, and 90 campuses of a dozen of the institutions have made it onto the accreditor’s “honor roll” since 2009.

For instance, researchers at the Center for American Progress found that the accreditor had named FastTrain College, in Miami, to its honor roll in 2011 — “a year before it was raided by the FBI and the owner charged with stealing millions from the federal government,” the report says.

The council has inadequate measures to verify the job-placement rate of its members, the study found, and has weaker standards for student recruitment, admission, and outcomes.

“In total, these results strongly suggest that ACICS is incapable of acting as a sufficient assessor of college quality and that its repeated poor judgment leaves millions of students and billions of taxpayer dollars at risk,” the study concluded.

The center’s study is the latest round of bad news for the accreditor, which has come under fire for accrediting many of the campuses of the now-bankrupt Corinthian Colleges. And it comes just three weeks before a federal panel that advises the U.S. education secretary on accreditation issues will decide whether to recommend removing the organization’s authority to allow access to Title IV money, such as Pell Grants or federally backed student loans.

An investigative news report from the website Buzzfeed asserts that a California institution accredited by the council, Northwestern Polytechnic University, employed grade inflation systematically to keep failing foreign students enrolled and paying their tuition. And the money from that tuition, which amounted to more than $77 million in 2014, was used to enrich the college’s owners, the news report found. The report has also spurred state and federal elected officials to call for the Education Department to take action against the accreditor.

The council, meanwhile, has announced a halt on accepting new member institutions until “the leadership of ACICS is satisfied that its program of assessment and review protects student interests, enforces high standards of quality, and contributes to the public good,” the accreditor’s acting executive director said in a news release.