Updated

Republican efforts to interview a former top aide to Michelle Obama in the controversial case of a fired inspector general have been stymied by the White House, the top Republican looking into the case said Tuesday.

The White House counsel's office has blocked Republican investigators from interviewing Jackie Norris, former chief of staff for the first lady, about President Obama's dismissal of former AmeriCorps Inspector General Gerald Walpin.

Republican investigators from the House Committee on Government Oversight and Reform have wanted to question Norris -- who is now senior adviser to the Corporation for National and Community Service, the organization that oversees AmeriCorps -- since they discovered earlier this month that she met with Alan Solomont, chairman of CNCS on June 9, the day before Walpin was fired.

Solomont was heavily involved in the Walpin firing, according to the Washington Examiner, which first reported the response by the first lady's office.

The White House move was revealed in a letter sent Monday to Norris by Rep. Darrell Issa, the ranking Republican on the oversight panel.

"Our request to meet with you was denied by (Corporation for National and Community Service) general counsel Frank Trinity," Issa wrote to Norris. "Mr. Trinity told my staff that the White House counsel's office has advised him that they were not permitting the corporation to make you available for an interview.

"The White House has averred that you had no role whatsoever in the president's decision to prevent your testimony. If the information provided by White House officials is true, it follows that no colorable claim of executive privilege should impede your cooperation with the committee," he continued.

Issa said in a statement Tuesday that he does not see a difference between this case and Democrats' pressing the political nature of the firings of nine U.S. attorneys under President George W. Bush.

"The removal of an IG who was conducting an investigation of one of the president's staunchest allies is no different than when President Bush fired a number of U.S. attorneys for political reasons, igniting a chorus of criticism and concern. The question is -- where is the outrage now that President Obama is doing the same thing?" he asked.

Walpin was the inspector general for the Corporation for National and Community Service until Obama pink-slipped him in June. Walpin filed one lawsuit in July arguing that the dismissal was politically motivated because of his probe of Sacramento Mayor Kevin Johnson, an Obama ally, and broke a 2008 law governing how watchdogs can be removed. In September Walpin filed an injunction requesting to be reinstated immediately.