The U.S. Interior Department’s acting inspector general has referred a probe into Interior Secretary Ryan Zinke’s conduct to the U.S. Justice Department for further investigation, the Washington Post reported on Tuesday, citing unnamed sources.

Mary Kendall, the acting inspector general of the Interior Department, is conducting at least three probes into Zinke’s conduct, including his involvement in a Montana land deal, and a decision not to grant two tribes approval to run a casino in Connecticut. It was not clear which probe had been sent to the Justice Department.

Reporting by Timothy Gardner; Editing by Lisa Shumaker