(CNN) Two major reports are expected this month from the Interior Department's inspector general, wrapping up two investigations that have been hanging over Secretary Ryan Zinke's head for several months.

A review of more than 30 reassignments of senior executive staffers -- many of whom were minorities or women -- could be completed by the end of this week. CNN reported last month that Zinke has been telling staff that he isn't focused on diversity. Meanwhile, some of the reassigned staffers complained they felt they were being retaliated against for political reasons.

Next week, another report is expected on Zinke's use of military and private aircraft, one a plane owned by pool executives, while traveling to his hometown and in the US Virgin Islands.

Over the past year, Zinke has faced numerous questions from media and Congress about his travel practices, and apparent mixing of business and personal travel.

He and other Cabinet members -- including Environmental Protection Agency Administrator Scott Pruitt, Housing and Urban Development Secretary Ben Carson and now-departed Health and Human Services Secretary Tom Price and Veterans Affairs Secretary David Shulkin -- have been under investigation and scrutiny for travel or personal-related spending throughout the past year.

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