Igor Danchenko, a Russia analyst who worked with Christopher Steele, the author of a dossier of rumors and unproven assertions about Donald J. Trump, was taken into custody as part of the Durham investigation.
Federal authorities on Thursday arrested an analyst who in 2016 gathered leads about possible links between Donald J. Trump and Russia for what turned out to be Democratic-funded opposition research, according to people familiar with the matter.
The arrest of the analyst, Igor Danchenko, is part of the special counsel inquiry led by John H. Durham, who was appointed by the Trump administration to scrutinize the Russia investigation for any wrongdoing, the people said.
Mr. Danchenko, was the primary researcher of the so-called Steele dossier, a compendium of rumors and unproven assertions suggesting that Mr. Trump and his 2016 campaign were compromised by and conspiring with Russian intelligence officials in Moscow’s covert operation to help him defeat Hillary Clinton.
The people familiar with the matter spoke on condition of anonymity because the indictment of Mr. Danchenko had yet to be unsealed. A spokesman for Mr. Durham did not respond to a request for comment.