President Donald Trump has furiously accused Hillary Clinton and the Democratic Party of using the investigation into Russian interference in the 2016 election as a “witch hunt for evil politics.”

In a lengthy Twitter rant Monday morning (AEST), Mr Trump wrote: “Never seen such Republican ANGER & UNITY as I have concerning the lack of investigation on Clinton made Fake Dossier (now $12,000,000?), the Uranium to Russia deal, the 33,000 plus deleted Emails, the Comey fix and so much more.

“Instead they look at phony Trump/Russia, ‘collusion,’ which doesn’t exist.”

The four tweets posted in the space of 24 minutes come a day after media reports emerged that a federal grand jury has approved the first charges in the investigation into alleged Russian meddling in the 2016 US presidential election.

Last week, The Washington Post reported that the Clinton campaign and the Democratic National Committee helped fund research that resulted in a dossier containing allegations about Mr Trump’s connections to Russia and possible coordination between his campaign and the Kremlin,

“The Dems are using this terrible (and bad for our country) Witch Hunt for evil politics, but the R’s …are now fighting back like never before. There is so much GUILT by Democrats/Clinton, and now the facts are pouring out. DO SOMETHING!” the President Tweeted Monday

Trump also said that the conversation about Russia was a distraction to prevent Republicans from passing tax reform.

“All of this “Russia” talk right when the Republicans are making their big push for historic Tax Cuts & Reform. Is this coincidental? NOT!” he wrote.

Never seen such Republican ANGER & UNITY as I have concerning the lack of investigation on Clinton made Fake Dossier (now $12,000,000?),….

— Donald J. Trump (@realDonaldTrump) October 29, 2017

…the Uranium to Russia deal, the 33,000 plus deleted Emails, the Comey fix and so much more. Instead they look at phony Trump/Russia,….

— Donald J. Trump (@realDonaldTrump) October 29, 2017

…"collusion," which doesn't exist. The Dems are using this terrible (and bad for our country) Witch Hunt for evil politics, but the R's…

— Donald J. Trump (@realDonaldTrump) October 29, 2017

…are now fighting back like never before. There is so much GUILT by Democrats/Clinton, and now the facts are pouring out. DO SOMETHING!

— Donald J. Trump (@realDonaldTrump) October 29, 2017

The reported indictment over Russian election collusion was sealed under orders from a federal judge so it was not clear what the charges were or who the target was, a source told Reuters on Sunday.

The filing of charges by the grand jury in Washington was first reported on Saturday by CNN, which said the target could be taken into custody as soon as Monday.

US intelligence agencies concluded in January that Russia interfered in the election to try to help Mr Trump defeat the Democratic candidate Mrs Clinton through a campaign of hacking and releasing embarrassing emails, and disseminating propaganda via social media to discredit her campaign.

Special counsel Robert Mueller, a former director of the Federal Bureau of Investigation, is investigating whether Trump campaign officials colluded with those Russian efforts.

“If the Special Counsel finds it necessary and appropriate, the Special Counsel is authorised to prosecute federal crimes arising from the investigation of these matters,” Deputy Attorney General Rod Rosenstein said in a May 17 letter appointing Mr Mueller.

Sources familiar with Mr Mueller’s investigation said he has used that broad authority to investigate links between Mr Trump aides and foreign governments as well as possible money laundering, tax evasion and other financial crimes.

In July, FBI agents raided the home in Virginia of Mr Trump’s former campaign manager, Paul Manafort, whose financial and real estate dealings and prior work for a pro-Russian political party in Ukraine are being investigated by Mr Mueller’s team.

Mr Mueller was appointed to lead the investigation a week after Trump fired FBI Director James Comey, who was heading a federal probe into possible collusion with Russia.

Mr Trump initially said he fired Mr Comey because his leadership of the FBI was inadequate and hurt morale, but in a later interview with NBC he cited “this Russia thing” as his reason.

– With agencies