New York (CNN) For months, the Trump administration hid a report showing that banks charged high fees to college students who opened accounts and held debit cards -- and that Wells Fargo charged more on average than any other financial institution.

The report, which was done by the Consumer Financial Protection Bureau, was only released publicly only last week after consumer advocacy groups submitted freedom of information requests for the document. A copy was sent from the agency to the Department of Education in February.

Seth Frotman, the former student loan ombudsman at the Consumer Financial Protection Bureau, had accused agency heads of burying the report when he quit in protest earlier this year.

"When new evidence came to light showing the nation's largest banks were ripping off students on campuses across the country by saddling them with legally dubious account fees, bureau leadership suppressed the publication of a report prepared by bureau staff," Frotman wrote in his resignation letter.

The report reviewed accounts at nearly 600 colleges that had partnered with banks for student promotions. Some banks paid colleges based on the number of students who opened accounts, the report said. Though most most students who signed up for these accounts did so without accruing fees, certain banks "pose a risk to student consumers," according to the report.

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