Democrats: Benghazi chairman ignores statement by GOP lawyer

Gowdy's actions, coupled with delays that have pushed the 2-year-old inquiry into the heat of the 2016 presidential race, "have damaged the credibility of the Select Committee beyond repair," Cummings and Smith wrote Sunday in a letter to Gowdy.

Republicans say the Obama administration has dragged its feet, failing to produce needed documents or interview subjects, delaying a final report.

Previous investigations blamed management failures at the State Department for a lack of security at the U.S. diplomatic mission in Benghazi, an issue that has dogged Clinton and other Obama administration officials.

Gowdy said comments by Stephen C. Hedger, assistant secretary of defense for legislative affairs, were "riddled with factual inaccuracies" and did "a disservice to the public" and employees at the Defense Department.

Hedger, in an April 28 letter to Gowdy, expressed frustration with the Benghazi panel, citing a "crescendo" of costly, duplicative and unnecessary requests, including a few based on claims made on Facebook or talk radio.