Hillary Clinton’s refusal to sit down with the State Department’s nonpartisan inspector general is “mind-boggling,” the chairman of the House Oversight Committee said on Wednesday.

“This is very uncommon,” Rep. Jason Chaffetz, R-Utah, said in an interview on Fox News. “Just look at the universe of just secretaries of state, past and current. [They] all sat down and did interviews with the inspector general. The only one that opted out was Secretary Clinton.