The latest of whom is Roger Stone, a longtime associate of Trump, who will appear before House Intelligence Committee next month.

According to Politico, Stone has in the past, strongly denied the notion that he or any others within the Trump campaign may have colluded with Russian Federation in its interference in the election.

Stone's lawyer, Robert Buschel, told Politico the July 24 hearing will be a closed session and that his client has repeatedly asked to publicly testify about his ties to Russian Federation and WikiLeaks on Capitol Hill.

John Podesta, the then-chairman of Hillary Clinton's presidential campaign, has revealed how the Russian linked hackers were successful in intruding into his computer.

Asked whether he thought Obama had done enough to counter Russian attempts to influence the election, Podesta said Tuesday, "I think the president and the entire administration were dealing with an unprecedented incidence of the weaponization of the fruits of Russian cyber activity, and I think they were trying to make the best judgments they could on behalf to the American people".

Just weeks later, Hillary Clinton's campaign chairman John Podesta's emails were hacked and released to WikiLeaks.

The fatal error? Podesta's IT person wrote back to his assistant calling the email "legitimate" when in fact he meant to say it was "illegitimate". "I may not be able to sue a member of Congress, but I sure as hell can sue the f-- out of Podesta".

Stone has denied co-ordinating with Russian Federation during the 2016 election, but he has acknowledged having a Twitter exchange with "Guccifer 2.0", a hacker that US officials believe has ties to Russian Federation. Parscale did not immediately respond to CNN request for comment Tuesday but previously told CNN on June 16 that he had not been contacted by any investigators - either federal or Congressional.

Stone has long wanted to talk to the Federal Bureau of Investigation and has been cooperating with the Senate and House intelligence committees regarding Russia, Buschel said. "I know my client looks forward to his testimony".