A federal grand jury has approved the first charges in the investigation into alleged Russian meddling in the 2016 US presidential election.

The indictment was sealed under orders from a federal judge, with US media reporting the target of the charges could be taken into custody as soon as Monday.

US intelligence agencies concluded in January that Russia interfered in the election to try and help Donald Trump defeat Democratic candidate Hillary Clinton.

This interference included a campaign of hacking, the release of embarrassing e-mails and the publication on social media of propaganda to discredit Mrs Clinton's campaign.

Special counsel Robert Mueller, a former FBI director, is investigating whether Trump campaign officials colluded with the Russian efforts.

Sources familiar with Mr Mueller's investigation said he has examined links between aides of Mr Trump and foreign governments, as well as possible money laundering, tax evasion and other financial crimes.

Peter Carr, a spokesman for Mr Mueller, declined to comment.

Mr Trump, who was elected president last November, has denied allegations that his campaign colluded with Russia and labelled the investigations as a "witch hunt".

The Kremlin in Moscow has also denied the claims.

Mr Mueller's team has interviewed former White House chief of staff Reince Priebus, former spokesman Sean Spicer and other current and former White House officials as part of the investigation.

In July, FBI agents raided the Virginia home of Mr Trump's former campaign manager, Paul Manafort.

His financial and real estate dealings and previous work for a pro-Russia political party in Ukraine are part of the investigation.

Michael Flynn, who briefly served as Mr Trump's national security adviser before he was fired in February for misleading vice president Mike Pence about the extent of his conversations with a Russian ambassador, is also under investigation.