The Consumer Financial Protection Bureau is accusing the Department of Education of getting in the way of its lawsuit against a student loan giant.

The accusation from the consumer watchdog comes in a case the agency filed last year against Navient, alleging the student loan company caused borrowers to struggle unnecessarily by steering them towards repayment plans that weren’t in their best interest and ignoring borrowers’ instructions about how their payments should be allocated, among other claims.

In a letter submitted to the judge overseeing the case this week, the CFPB claims that Navient isn’t producing documents requested as part of the case that are “essential to identifying the universe of harmed consumers,” because they don’t have permission from the Department of Education. The Department didn’t respond to a request for comment on the case.

Though it seems like a wonky regulatory battle, the letter is the latest sign of the tussle between the Department of Education, state lawmakers and the CFPB over whether student loan companies’ relationship with the Department of Education shields them from other legal challenges. Navient is also facing multiple suits from state law enforcement officials, including most recently, California’s attorney general.

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Politico reported earlier this year that the Department instructed student loan companies not to respond directly to any third party without first seeking the agency’s permission. In the spring, another major student loan company filed a lawsuit against the state of Connecticut’s Department of Banking, claiming that the state was requiring the firm to provide documents it didn’t have permission from the Department of Education to release.

Secretary of Education Betsy DeVos also released a memo earlier this year arguing that states can’t regulate student loan companies hired by the federal government, because state laws governing the companies are superseded by federal regulations.

“It appears that Secretary DeVos is siding with one of the most complained about companies in America to try to obstruct the ability of the Consumer Financial Protection Bureau to enforce consumer protection law for student loan borrowers,” said Chris Peterson, a senior fellow at the Consumer Federation of America, an association of consumer advocacy organizations.

Navient officials have a different opinion on the reason for the dispute. “This impasse is the result of the CFPB attempting to regulate the program of another federal agency,” Nikki Lavoie, a Navient spokesperson said in a statement. Navient has previously denied the allegations brought in the suit and Lavoie argued in the statement that the CFPB hasn’t found evidence to support its claims against the company. The request for the records “is an attempt to allow the search to continue,” she said. In addition, Navient’s contract with the Department requires the company to get the agency’s approval before sharing borrower data, she said.

On Friday, Navient filed its own letter to the judge in the case asking the court to hold an in-person conference regarding the issue and to give Department the opportunity to be heard on it. “This issue is, fundamentally, a dispute between two agencies of the federal government,” an attorney representing Navient wrote.

According to the CFPB, the Department is citing the Privacy Act, which governs how federal agencies handle information they collect, as a justification for blocking the release of the Navient documents.

Though the goal of the Privacy Act is to make sure government agencies abide by fair information practices, it does allow disclosure in certain circumstances, including when another agency is requesting the information and if it’s part of a court order, said Peter Swire, a privacy expert and professor at Georgia Tech’s Scheller College of Business.

“The Privacy Act recognizes that other agencies might need the records and the Privacy Act creates a way for the requesting agency to get the records,” he said.

The Department and the CFPB have historically shared information about student loan companies, but the Department ended their information sharing agreement last year, calling the CFPB “overreaching and unaccountable.”