Former White House adviser Steve Bannon answered questions from Special Counsel Robert Mueller's team for two days this week.
However, he then frustrated politicians by remaining tight-lipped during testimony to the House Intelligence Committee yesterday.
Three sources familiar with the Mueller proceedings said Mr Bannon was interviewed for a total of about 20 hours by Mr 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 Mr Bannon was questioned on topics including his knowledge of President Donald Trump's reasons for firing James Comey as FBI director last year, as well as dealings with the Russian ambassador by former national security adviser Michael Flynn and Mr Trump's son-in-law, Jared Kushner.
In contrast, leaders of the US House of Representatives Intelligence Committee's Russia investigation said Mr Bannon, Mr Trump's former strategist and a key player in Mr 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 Mr Bannon.
Mr Bannon also refused to answer many questions during his first appearance before the intelligence panel on 16 January.
Declining to discuss with the committee the weeks after the November 2016 presidential election and before Mr Trump's inauguration, or his own time at the White House, Mr Bannon claimed executive privilege and special protections for presidential communications in refusing to say more, politicians said.
Mr Bannon's attorney and White House aides did not immediately respond to requests for comment.
