“Glenn Simpson, the co-founder of investigative firm Fusion GPS, met with staff of the Senate Judiciary Committee as part of the committee’s investigation into Russian meddling and potential collusion with the Trump campaign in the 2016 presidential election.A committee spokesperson did not give Fox News any further information on the meeting with Simpson and Judiciary staff, though a source confirmed that Fusion GPS has given the Senate committee over 40,000 documents.

“Mr. Simpson told Congress the truth and cleared the record on many matters of interest to congressional investigators,” his attorney Josh Levy told Fox News.

Simpson’s company was behind the dossier that was compiled during last year’s campaign and which contained crude allegations against now-President Trump.

Committee Chairman Chuck Grassley, R-Iowa, and committee Ranking Member Sen. Dianne Feinstein, D-Calif., originally had issued a subpoena for Simpson’s testimony at a public hearing before the committee last month. But they withdrew it after Simpson reached arrangements to interview with the committee in private.”

WATCH ABCNews on the Glenn Simpson Testimony

HOW EX-SPY CHRISTOPHER STEELE COMPILED HIS EXPLOSIVE TRUMP-RUSSIA DOSSIER  The man behind the infamous dossier that raises the possibility that Donald Trump may be vulnerable to Kremlin blackmail is Russia expert Christopher Steele, formerly of M.I.6. Here’s the story of his investigation. APRIL 2017 Vanity Fair 

RUSSIA PROBE: DEMOCRATS BLOCK KEY WITNESS AGAINST SHADOWY FIRM FUSION GPS

“The committee’s hearing in July pertained to oversight of the Foreign Agent Registration Act (FARA). At the public session, CEO and founder of Hermitage Capital Bill Browder testified that Fusion GPS and Simpson worked “on behalf of the Russian government” in an effort to fight U.S. sanctions that had enraged Moscow’s elite.

Browder told lawmakers that Russian lawyer Natalia Veselnitskaya, who met with Donald Trump Jr. at Trump Tower in June 2016, also was responsible for hiring Simpson to “conduct a smear campaign against me and Sergei Magnitsky in advance of a congressional hearing on the Global Magnitsky Act.” The Magnitsky Act is a U.S. law that brings sanctions against Russian oligarchs suspected of money laundering.”

Wikipedia: “Aleksej Gubarev, chief of technology company XBT and a figure mentioned in the dossier, sued BuzzFeed for defamation on February 3, 2017. The suit, filed in a Broward County, Florida court,^[76] centers on allegations from the dossier that XBT had been “using botnets and porn traffic to transmit viruses, plant bugs, steal data and conduct ‘altering operations’ against the Democratic Party leadership”.^[77]

^[76]“Russian Executive Sues BuzzFeed Over Unverified Trump Dossier”  New York Times  February 3, 2017

^[77]“BuzzFeed sued over its publication of uncorroborated Trump dossier”  McClatchy DC May 2, 2017

Spy behind Trump dossier says info was never meant for public eyesCNN  May 3, 2017

FIRM BEHIND ANTI-TRUMP DOSSIER ALSO WORKED FOR RUSSIA, SENATE WITNESS SAYS

After the hearing, Fusion GPS responded to Browder’s allegations — saying they had “complied with the law” and were “not required to register under FARA,” and “did not spread false information about William Browder or Sergei Magnitsky.”

“What is clear is that the president and his allies are desperately trying to smear Fusion GPS because it investigated Donald Trump’s ties to Russia,” Fusion GPS said in a statement to Fox News last month. “They have pulled out all the stops, including this false allegation about FARA.”

Conservative Website First Funded Anti-Trump Research by Firm That Later Produced Dossier

UK was given details of alleged contacts between Trump campaign and Moscow In December the UK government was given reports by former MI6 officer Christopher Steele on possible collusion between Trump camp and the Kremlin   The Guardian   April 28, 2017