BOSTON (AP) — Democrats in Congress are accusing the Education Department of interfering with an investigation by the agency's independent watchdog.

Five lawmakers sent a letter to Secretary Betsy DeVos on Tuesday staying her deputy pressured the department's inspector general on Jan. 3 to drop an internal investigation .

When the inspector general said she would continue the inquiry, she was told weeks later she was being replaced. That decision was quickly reversed after it became public.

A department spokeswoman did not immediately provide comment.

The investigation is examining DeVos' decision to reinstate a troubled accrediting agency that was shut down by the Obama administration.

In the letter, lawmakers including Virginia Rep. Bobby Scott and Washington Sen. Patty Murray demand answers from DeVos and say they are "increasingly concerned" about the department's actions.