Paul Manafort was charged today with conspiring to defraud the US following an inquiry into allegations Russia interfered in the US election.
But the charges do not appear to relate to Mr Trump’s campaign and instead focus on Mr Manafort and associate Rick Gates’ business dealings in Ukraine up to 2016.
An angry President Trump lashed out on Twitter this afternoon, writing: “Sorry, but this is years ago, before Paul Manafort was part of the Trump campaign.
“But why aren’t Crooked Hillary & the Dems the focus?????
“….Also, there is NO COLLUSION!”
Mr Manfort, 68, served the Trump campaign from June to August of 2016 before resigning amid reports he may have received millions in illegal payments from a pro-Russian political party in Ukraine.
Mr Gates was a long-time business partner of Mr Manafort and also served as his deputy during his brief tenure as Trump’s campaign chairman.
Both men surrendered to federal authorities on Monday in the first charges stemming from an investigation by special counsel Robert Mueller.
The probe had been launched to examine alleged Russian meddling in last year’s election campaign aimed at swaying the vote in favour of Mr Trump.
Today, the pair were indicted by a federal grand jury on 12 counts including conspiracy against the United States, conspiracy to launder money and violating federal lobbying and banking laws.
The indictment claimed the two men generated tens of millions of dollars of income from work for Ukrainian political parties and leaders.
It is also claimed laundered money through US and foreign entities to hide payments between 2006 and at least 2016.
The charge of conspiracy to commit money laundering carries a maximum 20-year prison sentence.
A Trump adviser said today: “As it relates to the president, this is nothing.
“It had nothing to do with their tenure at the campaign as far as I can tell.”
The US President has previously denied any allegations of collusion with the Russians and called the probe “a witch hunt.” The Kremlin also has denied the allegations.
However, US intelligence agencies concluded earlier this year that Moscow interfered in the campaign, including by hacking into and releasing Democratic emails in order to try to embarrass party candidate Hillary Clinton.