The Education Department’s sweeping crackdown on fraudulent practices at for-profit colleges has stalled under the Trump administration’s appointees, several current and former department employees say.

Current and former employees, who requested anonymity for fear of retaliation, said tight restrictions have been put on staff members scrutinizing for-profit institutions, constraining their contact with other state and federal agencies without high-level approval — a contention a department spokesman denied.

Some state officials who had collaborated with the Education Department in bringing legal cases against for-profit schools say their joint work has ground to a halt. They also say they are troubled by an apparent slowdown in granting debt relief to students who were cheated.

“The department has become a black box since the Obama administration left the building,” said Maura Healey, the Massachusetts attorney general, whose office is one of dozens that have been involved in prominent cases against the for-profit sector.