Complex sentence: Selig left the Commerce Department in late June 2016, as the Inspector General's office was completing an investigation of his expense reimbursements for luxury hotels while traveling on behalf of the department.
Split into simpler sentences: Selig left the Commerce Department in late June, 2016. Months after leaving, the Inspector General's office completed an investigation of Selig's office's expense reimbursements for luxury hotels while traveling on behalf of the department.