Paul Manafort, US President Donald Trump's former election campaign manager, struck a covert deal with Kremlin-affiliated Russian oligarch Oleg Deripaska in 2006 to promote the interests of President Vladimir Putin abroad, the Associated Press reported on March 22, citing documents it obtained supporting the charge.

Manafort proposed a strategy to nullify anti-Russian opposition across former Soviet republics a decade ago, according to AP, although Manafort has insisted that he never worked for Russian interests.

The allegations open a new chapter in the US public discussion and official investigation of possible undeclared ties between Trump and Putin, whose intelligence services are accused of meddling in the outcome of November's US presidential election.

Manafort's name featured prominently during the US Senate hearing with the heads of the FBI and NSA intelligence agencies on March 20, in the context of suspected Russian influence on members of Trump's team and the US elections.

Reportedly, Manafort received $10mn yearly, totalling $40mn, for implementing his own political strategy of undermining the anti-Russian opposition in the CIS region, as well as promoting Russia's image in the US and Europe.

Manafort's links to Russia required him to resign as Trump's campaign manager during the US presidential race, amid revelations about his past lucrative involvement with Ukraine's pro-Russian ex-president Victor Yanukovich.

Yanukovich, now exiled in Russia, was ousted from power in February 2014 prior to Russia's annexation of the Crimea peninsula and intervention in East Ukraine.

Both Deripaska and Manafort confirmed having past working ties, but denied that those involved promotion of Russian political interests. 

Other members of Trump's camp have also come under fire for direct contacts with Russian officials. US Attorney General Jeff Sessions met with Russian ambassador Sergey Kislyak twice last year, first on the sidelines of the Republican convention in July, and in September in his office when he was a member of the Senate Armed Services Committee.

At the time a Republican senator for Alabama, Sessions campaigned on behalf of Trump during 2016. National Security Advisor Michael Flynn also had to resign after it emerged that he had undisclosed meetings with Kislyak before the 2016 elections.

Meanwhile, CNN on March 23 cited unnamed US officials claiming that the FBI has information connecting Trump associates with suspected Russian spies in the release of information damaging to Hillary Clinton's election campaign.