Rep. Darrell Issa (R-Calif.) says Congress asked Hillary Clinton in Dec. 2012 whether she was using a personal email account and never received a response. 

Issa, who was then the chairman of the House Committee on Oversight and Government Reform, sent the letter to the then-secretary of state and 17 other Obama cabinet secretaries.

The State Department's only response was an outline of its email policies and it was sent to Issa months later, after Clinton had left her post.

Issa was investigating the possible use of private email accounts by Obama administration officials after questions were raised about EPA officials using private email aliases

Clinton's campaign downplayed the latest twist in the private email saga, arguing "there is nothing new here."

"This was a letter sent to all cabinet agencies leaked to the press two years later at the start of Hillary Clinton's campaign," said Clinton spokesman Nick Merrill.

"The letter was sent shortly before she left the State Department and was responded to in due course. As we've said before, as Secretary, she followed the letter and the spirit of the law. She has provided all of her work email to the State Department and has asked the State Department to release them publicly as soon as possible."

Issa reacted on "America's Newsroom" this morning, disputing that Clinton followed the letter or the spirit of the law. He said his investigation of the Obama administration's email practices was well known at the time and the letter was released publicly. 

Issa said investigations into scandals like Solyndra "showed they were deliberately circumventing the law" by using private accounts, like Gmail, instead of .gov addresses.

"We never would have suspected she set up a server in her own home so she could truly clandestinely communicate," said Issa. 

Watch the full interview above and check out "The O'Reilly Factor," tonight at 8/11p ET as Bill addresses the first week of the Clinton campaign in his Talking Points Memo.