District of Columbia: Former top White House aide Steve Bannon appeared Tuesday at the House Intelligence Committee to testify behind closed doors in its sensitive probe into the Trump campaign`s links to Russia.
It is the first time Bannon has testified in the probe of whether campaign associates of the president colluded with Russia in its bid to influence the 2016 US elections.
It was not likely to be Bannon`s last such testimony: the New York Times reported Tuesday that Bannon has been subpoenaed by Robert Mueller, the Justice Department special counsel investigating the same issue.
That made Bannon the first person from President Donald Trump`s inner circle to receive a grand jury subpoena from Mueller in the probe, which is also looking at whether Trump has tried to obstruct the investigation.
The testimony of Trump's estranged political strategist could be explosive: he had a front-row seat as chief executive of the 2016 election campaign in its final months, and as a top policy advisor in the first seven months of the administration.
An incendiary book released last week, "Fire and Fury: Inside the Trump White House," by Michael Wolff, quoted him as saying that a pre-election meeting involving Trump`s eldest son Donald Jr. and a Kremlin-linked Russian lawyer was "treasonous."
Wolff, who painted a picture of an erratic and poorly informed president, was given substantial access to the White House during Trump`s first year by Bannon.
A hard-line nationalist who sought to shake up US domestic and foreign policy, Bannon, 64, was forced out as Trump`s chief strategist in August.
His actions since then -- most notably supporting the failed Senate campaign of Alabama Republican Roy Moore, but also his comments in the Wolff book -- have left him increasingly isolated in conservative circles.
Last week he stepped down from Breitbart News, which he had helped make a powerful conservative force, and he lost the support of the Mercer family, wealthy conservative power brokers.
Underscoring the break, Trump said Bannon had "lost his mind" and branded him "Sloppy Steve" via Twitter.