Steve Bannon, a former chief strategist to US President Donald Trump, is testifying on Capitol Hill in a probe of alleged ties between Russia and Trump's 2016 presidential campaign. He has been subpoenaed by Special Counsel Robert Mueller. This appears to be the first time the Special Counsel has used a subpoena against a member in President Trump's inner circle. CGTN's Jim Spellman tell us more details from Washington DC.

The New York Times is now reporting that Steve Bannon has been subpoenaed to testify before the special counsel in the ongoing investigation into alleged Russian interference in the US presidential election. Bannon is also testifying before the House Intelligence Committee behind closed doors Tuesday.

A subpoena means he must testify and answer all of the panel's questions or risk being found in contempt of court. Other members of the campaign and White House staff have spoken to the Special Counsel voluntarily. This appears to be the first time the Special Counsel has used a subpoena to compel someone in President Trump's inner circle to testify.

In the recently released book, Fire and Fury, Bannon is quoted as saying a meeting between Trump campaign officials and individuals linked to Russia was quote "treasonous." The author of the book says Bannon became disenchanted with Trump.

MICHAEL WOLFF AUTHOR OF FIRE AND FURY "I think that he had come to be sorely disillusioned with Donald Trump. I think and this was from both from a political side and a gender side and from a personal side of having to work with Donald Trump which I think is the maybe the ultimate in trying experiences."

It's no surprise the Special Counsel would like to speak with a disillusioned Steve Bannon, but the subpoena seems to indicate they may consider his testimony as essential to the case. Trump has repeatedly said he did nothing wrong and that there was no collusion with Russians.