House Democrats have called on Treasury Secretary Steven Mnuchin to deliver a classified briefing Thursday regarding the Trump administration's plans to end sanctions affecting several companies tied to Russian billionaire Oleg Deripaska, according to the New York Times.

In April, the Trump administration hit three companies Deripaska controls with sanctions over Russian interference in the 2016 US elections; EN+, Rusal and JSC EuroSibEnergo. Following the announcement, the Treasury Department delayed their implementation - eventually deciding in December that they would be lifted following an aggressive lobbying campaign by Deripaska's network.

Democratic lawmakers sent Mr. Mnuchin a letter on Tuesday seeking an explanation for why the termination of the sanctions was justified. They expressed concern that Mr. Deripaska still maintained “significant ownership” of En+, the holding company that controls Rusal, while transferring shares to VTB, a sanctioned Russian bank. They also said that the government shutdown was hampering their ability to properly review the decision. The solution approved by the Treasury Department lifts the sanctions against Mr. Deripaska’s companies in exchange for reducing his stake in EN+ from approximately 70 percent to less than 45 percent, and giving up control of that company and Rusal. -New York Times

Deripaska, who had business dealings with former Trump campaign chairman Paul Manafort, was rumored to be Donald Trump's "back channel" to Russian President Vladimir Putin. The Russian oligarch hit back in September - admitting to "collusion" when he served as an FBI asset during the Obama administration.

Deripaska spent $25 million of his own money to bankroll an FBI-supervised operation to rescue a retired FBI agent - Robert Levinson, who was kidnapped in 2007 while working on a 2007 CIA contract in Iran.

FBI agents courted Deripaska in 2009 in a series of secret hotel meetings in Paris; Vienna; Budapest, Hungary, and Washington. Agents persuaded the aluminum industry magnate to underwrite the mission. The Russian billionaire insisted the operation neither involve nor harm his homeland. -The Hill

The FBI then tried to turn Deripaska into an FBI informant - an effort involving twice-demoted DOJ #4 official Bruce Ohr and Christopher Steele - the author of the largely unverified "Steele Dossier."

The attempt to flip Mr. Deripaska was part of a broader, clandestine American effort to gauge the possibility of gaining cooperation from roughly a half-dozen of Russia’s richest men, nearly all of whom, like Mr. Deripaska, depend on President Vladimir V. Putin to maintain their wealth, the officials said. -NYT

Meanwhile, in a September 2016 meeting, Deripaska told FBI agents that it was "preposterous" that Paul Manafort was colluding with Russia to help Trump win the 2016 election. This, despite the fact that Deripaska and Manafort's business relationship "ended in lawsuits, per The Hill - and the Russian would have every reason to throw Manafort under the bus if he wanted some revenge on his old associate.

So the FBI and DOJ secretly collaborated with Trump's alleged backchannel over a seven-year period, starting with Levinson, then on Deripaska's Visa, and finally regarding whether Paul Manafort was an intermediary to Putin. Deripaska vehemently denies the assertion, and even took out newspaper advertisements in the US last year volunteering to testify to Congress, refuting an AP report that he and Manafort secretly worked on a plan to "greatly benefit the Putin government" a decade ago.

Soon after the advertisements ran, representatives for the House and Senate Intelligence Committees called a Washington-based lawyer for Mr. Deripaska, Adam Waldman, inquiring about taking his client up on the offer to testify, Mr. Waldman said in an interview. What happened after that has been in dispute. Mr. Waldman, who stopped working for Mr. Deripaska after the sanctions were levied, said he told the committee staff that his client would be willing to testify without any grant of immunity, but would not testify about any Russian collusion with the Trump campaign because “he doesn’t know anything about that theory and actually doesn’t believe it occurred.” -NYT

In short, Deripaska wanted it known that he worked with the FBI and DOJ, and that he had nothing to do with the Steele dossier.

Today, Deripaska is banned anew from the United States, one of several Russians sanctioned in April by the Trump administration as a way to punish Putin for 2016 election meddling. But he wants to be clear about a few things, according to a statement provided by his team. First, he did collude with Americans in the form of voluntarily assisting and meeting with the FBI, the DOJ and people such as Ohr between 2009 and 2016. He also wants Americans to know he did not cooperate or assist with Steele’s dossier, and he tried to dispel the FBI notion that Russia and the Trump campaign colluded during the 2016 election. -The Hill

All of that said, the Russian billionaire will still remain on the US sanctions list, personally, despite the removal of his companies.