Deputy Attorney General Rod Rosenstein appointed Mr Mueller to lead the Russian Federation investigation in May after Mr Trump fired FBI Director James Comey, who had had originally been in charge of the bureau's probe.
The committee is one of several congressional panels investigating potential ties between Russian Federation and the Trump campaign.
A question investigators are asking is whether Mr Manafort knew of Trump campaign dealings with Russia.Congressional committees are looking at a June 2016 meeting a Russian lawyer had with Mr Trump's son, Donald Trump Jr. As former GOP congressman Bob Barr aptly put it in the MDJ recently, Mueller "is sure to find something".
"Mr. Manafort is in the process of retaining his former counsel, Miller & Chevalier, to represent him in the office of special counsel investigation", Manafort's spokesperson told BuzzFeed News in a statement. "This highly significant step reaffirms the reasons that I first urged the appointment of a Special Counsel with the power to execute such investigative measures and bring criminal charges and redoubles my determination to protect this investigation from political interference". However it is a secret part of the investigation.
"I thought it was a very, very strong signal, or whatever", Trump said when asked about the raid, adding that he had not spoken to the attorney general or Federal Bureau of Investigation about it. "There never really was any to begin with, to tell you the truth".
In fact, Manafort served as Trump's campaign manager for almost half a year during the critical period of the campaign when Trump wrapped up the nomination.
Manafort has long had Russian connections; before he ran the Trump campaign, he dealt with a lot of pro-Russian oligarchs and politicians.
Others close to Manafort have been pulled into the investigation: Manafort's son-in-law and occasional partner in real estate deals, Jeffrey Yohai, who's now being sued for fraud by a former investor, provided documents and information to investigators during a meeting in NY two months ago, CNN reported Thursday.
Committee officials also told CNN that Grassley, the chairman of the committee, and Feinstein, the top Democrat on the panel, were able to review the memos that Comey wrote after his interactions with Trump, including his allegations that Trump urged him to back away from investigating Flynn and sought loyalty from the fired Federal Bureau of Investigation director.
An attorney for Yohai declined to comment. "Not just to the judge, but to the public".
"If that was the case, Paul would have switched months ago", Maloni said, pointing to the fact that Mueller was appointed to lead the FBI investigation in May. "The investigation of Mrs. Clinton didn't even use a grand Jury".
"But the landscape has shifted", he said.
According to financial records, Mr Manafort had bank accounts in Cyprus - a tax haven often used for money laundering.
Josh Rosenstein, an attorney at Sandler Reiff Lamb Rosenstein & Birkenstock who specializes in FARA, said that although prosecutions under the act are quite rare, it is a "distinct possibility" that Mueller's team could pursue one against Manafort. Whatever financial crimes Manafort may have committed and may or may not get charged with are certainly not the end goal here. It's possible another person in Trump's inner circle could be called upon by congressional investigators: Trump's longtime personal assistant, Rhona Graff. Reuters reports that Manafort has previously been represented by Miller & Chevalier's Richard Hibey, whose previous clients include Clair George, a former Central Intelligence Agency deputy director convicted of lying to Congress about the Iran-Contra scandal. "I was very, very surprised to see it", Trump said from his golf club in Bedminster, New Jersey, Thursday, according to pool reports.