By Patricia Zengerle and Karen Freifeld
WASHINGTON (Reuters) - Former White House adviser Steve Bannon answered questions from Special Counsel Robert Mueller's team for two days this week, but then frustrated lawmakers by remaining tight-lipped during testimony to the House Intelligence Committee on Thursday.
Three sources familiar with the Mueller proceedings said Bannon was interviewed for a total of about 20 hours by Mueller's investigators and prosecutors. One said he had answered a range of questions, unlike his refusal to do so before the House intelligence panel.
Another said Bannon was questioned on topics including his knowledge of President Donald Trump's reasons for firing James Comey as Federal Bureau of Investigation director last year, as well as dealings with the Russian ambassador by former national security adviser Michael Flynn and Trump's son-in-law, Jared Kushner.
In contrast, leaders of the U.S. House of Representatives Intelligence Committee's Russia investigation said Bannon, Trump's former strategist and a key player in Trump's 2016 election campaign, would answer only 25 questions approved by the White House.
Representative Adam Schiff, the panel's top Democrat, called for the initiation of contempt of Congress proceedings against Bannon. Bannon also refused to answer many questions during his first appearance before the intelligence panel on Jan. 16.
Declining to discuss with the committee the weeks after the November 2016 presidential election and before Trump's inauguration, or his own time at the White House, Bannon claimed executive privilege and special protections for presidential communications in refusing to say more, lawmakers said.
Bannon's attorney and White House aides did not immediately respond to requests for comment.
"He did not answer all the questions we'd like answered, so there was frustration among committee members with respect to that," said Republican Representative Mike Conaway, who has been overseeing the committee's investigation of Russia and the 2016 U.S. election.
A source familiar with his appearance before the committee said Bannon told lawmakers he was "not authorized to answer" about 35 times, and answered "no" to all of the 25 questions that had been authorized by the White House.
U.S. intelligence agencies determined more than a year ago that Moscow sought to interfere in the campaign. The investigations by congressional committees and Mueller's team have shadowed the first year of Trump's campaign.
Russia has denied trying to meddle in the election. Trump, a Republican, has denied collusion between his associates and Moscow. Mueller has been conducting a criminal investigation of possible collusion between Russia and Trump's campaign to sway the 2016 presidential election.
"There was a refusal to answer any questions that would have brought out the full facts. That is not how privilege works. That's how stonewalling works," Schiff told reporters.
Conaway said attorneys would have to consider the claims of privilege, and there would have to be discussions with House Speaker Paul Ryan and other officials about whether a contempt proceeding was appropriate.
"I think he (Bannon) should answer our questions," he told reporters.
Trump fired Bannon, the former head of the hard-right Breitbart News website, from his White House position in August. Bannon had been a close Trump associate since he joined the Trump campaign and helped the political novice defeat Democrat Hillary Clinton in 2016.
Reuters reported last week that Bannon was expected to meet with Mueller this week.
(Additional reporting by Steve Holland, Mark Hosenball and John Walcott; Editing by Leslie Adler and Peter Cooney)