Igor Danchenko, a Russia analyst who gathered material for the Steele dossier, said he found his sources credible but that he took their information with a “grain of salt.”Jonah M. Kessel | The New York Times/ReduxAn analyst who contributed research to the so-called Steele dossier that detailed alleged ties between ex-President Donald Trump and Russia during the 2016 election was arrested Thursday as part of an ongoing probe by special counsel John Durham.Igor Danchenko, the analyst, is the third person criminally charged in Durham’s investigation, which is focused on the origins of the federal probe into the Trump campaign’s suspected coordination with Russian agents to influence the outcome of the 2016 race for the White House.The Department of Justice, without revealing the charge against him, said that Danchenko was taken into custody Thursday morning. He is due to appear in federal court in Virginia on Thursday afternoon.Christopher Schafbuch, a lawyer who represented Danchenko in a 2017 civil case, would not confirm or deny that he was currently Danchenko’s lawyer.CNBC PoliticsRead more of CNBC’s politics coverage:In September, Durham obtained an indictment against then-Perkins Coie law firm partner Michael Sussman for allegedly lying to the FBI when he offered a tip in 2016 about the possible secret electronic channel between Trump’s company and a Russian bank. Sussman has denied the allegation.In January, a former FBI lawyer, Kevin Clinesmith, was sentenced to probation for having falsified a claim that was used to maintain surveillance of former Trump advisor Carter Page,Dancheko had worked for former British spy Christopher Steele, whose dossier on Trump became the basis for the application of an FBI warrant to tap the phone of Page a month before Election Day that year.Steele’s inquiry was funded by the firm Fusion GPS, which itself had been hired by the Democratic National Committee to conduct opposition research on the then-Republican candidate Trump.Christopher Steele, the former MI6 agent in London where he speaks to the media for the first time, March 7, 2017.Victoria Jones | PA Images | Getty ImagesTrump and his allies have strongly criticized the Steele dossier, which contains unsubstantiated and refuted claims.They have argued that the entire original federal probe into Trump’s ties to Russia and possible obstruction of justice by Trump for seeking to undercut the inquiry was groundless and tainted by political motivations because of the Steele dossier.The investigation by former special counsel Robert Mueller found that there was an aggressive effort by Russian agents to use social media and computer hacking to help Trump’s bid to win the presidency over Democratic nominee Hillary Clinton. But Mueller said he did not find enough evidence to charge Trump campaign affiliates with conspiring with the Russians in that effort.Mueller also did not charge Trump with any wrongdoing, but his final report pointedly did not exonerate the then-president.”If we had had confidence that the president clearly did not commit a crime, we would have said so,” Mueller told reporters in 2019.Mueller did file more than 100 criminal charges being filed against three Russian companies and nearly three dozen individuals, including half a dozen former Trump advisors, among them former Trump campaign chief Paul Manafort.Durham was tasked with investigating the roots of the Trump-Russia probe during the Trump administration. Trump himself had repeatedly called the probe a “witch hunt.” Trump has also repeatedly expressed frustration with Durham’s investigation, which to date has not resulted in an official refutation of the findings of Mueller’s probe.