Democrats are demanding that the FBI investigate Attorney General Jeff Sessions.
The request originates from Democrats serving on the House Judiciary Committee who are urging Sessions' Russian links be investigated by America's senior police force.
It appears that the Trump ally met Russian ambassador Sergei Kislyak during the Republican President's campaign last year.
He also serves as a policy adviser to the billionaire, yet he failed to declare the communications when he was asked at his confirmation hearing in last month whether anybody who served on the Republican's campaign had been communicating with the Russians.
'Unbelievable and false'
The Trump ally hit back at these claims, saying that he did not discuss 'any political campaign' with Moscow during the reality star's bid to enter the White House.
He called the allegations 'unbelievable and false.'
However, a letter sent to FBI Director James Comey from the Judiciary Committee has specified they want 'immediate criminal investigations into these statements which could potentially implicate a number of criminal laws including Lying to Congress and Perjury.'
The Attorney General said in January: 'I'm not aware of any of those activities. I have been called a surrogate at a time or two in that campaign and I did not have any communications with the Russians.'
Yet it is apparent that he met Kislyak in September 2016 and held a group meeting, too.
This serves as a devastating blow to the Trump presidency as the policy adviser was also an established member of the Senate Armed Services Committee.
Despite this, the Attorney General's spokesperson said that he does not have a 'strong recollection' of their discussions, and that he attended the meeting in his position as a senator.
'Must resign immediately'
Trump's enemies are accusing him of lying to Congress and that he used these meetings to help coordinate the defeat of Democrat candidate Hillary Clinton, who was portrayed as 'unfavourable' to Mr. Putin.
House minority leader Nancy Pelosi said that he must resign immediately.
She added: 'There must be an independent, bipartisan, outside commission to investigate Trump's political, personal and financial connections to the Russians.'
There is now a proceeding federal investigation into Moscow's links to the election, which Trump's ally will oversee.
'Must remove himself from the federal investigation'
Controversially,senior Republicans have suggested he remove himself from the federal investigation.
But the policy adviser has only guaranteed to do so if necessary.
Putin is under heavy scrutiny from the CIA for interfering in the 2016 presidential election.
The Republicans' national security adviser, Michael Flynn, also resigned after discussing sanctions with the Russian ambassador prior to the former reality star's successful bid, and humiliated Vice President Mike Pence.
Jeff Sessions was appointed by Donald Trump as the United States' head of the Department of Justice, which is responsible for enforcing federal law. His promotion as Attorney General was a reward after emerging as the first senator to endorse the billionaire last year.
