Washington (CNN) President Donald Trump's former campaign chief Paul Manafort pushed back Wednesday on a report that he allegedly earned millions of dollars by helping Russian President Vladimir Putin's government push its interests around the world.

Manafort confirmed that he worked for Oleg Deripaska, a Russian billionaire with close ties to Putin, but rejected an Associated Press report alleging that work was aimed at furthering the political interests of Putin's government.

"I worked with Oleg Deripaska almost a decade ago representing him on business and personal matters in countries where he had investments. My work for Mr. Deripaska did not involve representing Russian political interests," Manafort said in a statement his spokesman provided to CNN.

He issued another statement on the matter Wednesday afternoon: "I have always publicly acknowledged that I worked for Mr. Deripaska and his company, Rusal, to advance its interests. For example, one of the projects involved supporting a referendum in Montenegro that allowed that country to choose membership in the (European Union), a measure that Russia opposed. I did not work for the Russian government. Once again, smear and innuendo are being used to paint a false picture. I look forward to meeting with those conducting serious investigations of these issues to discuss the actual facts."

Manafort was referring to the 2006 referendum that resulted in Montenegro's independence from Serbia and Montenegro, which set the country on a more pro-Western path.

A spokesman for Deripaska told CNN on Wednesday that Manafort provided "investment consulting services" but declined to provide any additional details.

"There was an agreement between Mr. Deripaska and Mr. Manafort to provide investment consulting services related to business interests of Mr. Deripaska which now is a subject to legal claims," the spokesman said in a statement.

The Associated Press reported Wednesday that Manafort pitched a plan to Deripaska to "greatly benefit the Putin government" and was subsequently paid millions of dollars, according to business records obtained by the AP and interviews the news outlet conducted with sources familiar with the matter.

It is just the latest report pointing to a link between Manafort and Russian interests.

Before he was brought aboard the Trump campaign, Manafort was well known for having served as an adviser to Ukrainian President Viktor Yanukovych, who was close to Putin and fled to Russia after he was ousted in the 2014 political crisis. Manafort was later named in a Ukrainian government investigation last summer after a ledger detailed millions of dollars in secret payments to Manafort, which he denied.

Manafort's connections to Russia faced fresh scrutiny last month after current and former US officials told CNN that high-level Trump campaign advisers, including Manafort, regularly communicated with Russians known to US intelligence. Manafort called the allegation "100% not true" and said he didn't "remember talking to any Russian officials, ever."

White House press secretary Sean Spicer on Wednesday said Trump "did not know" of Manafort's work as disclosed in the AP report.

"I think nothing in this morning's report references any actions by the President, the White House or any Trump administration official," Spicer said during the White House briefing.

Spicer rejected the notion that Trump should have known about the work, asking in return whether Trump should have known who Manafort "played with in the sandbox."

That came two days after Spicer sought to diminish Manafort's role in the campaign, claiming he played a "limited role" even though Manafort was campaign chairman and effectively took over as campaign manager after the firing of Trump's first campaign manager, Corey Lewandowski. Manafort worked on the campaign from March until August 2016.

"To start to look at some individual that was there for a short period of time, or, separately, individuals who really didn't play any role in the campaign, and to suggest that those are the basis for anything is a bit ridiculous," Spicer said Monday during a White House briefing.

The Associated Press report comes days after FBI Director James Comey confirmed in testimony to Congress that his agency is investigating Russian meddling in the 2016 campaign and potential ties between Trump campaign associates and the Russian government.

Sen. Susan Collins, R-Maine, said Wednesday that the new reports about Manafort are likely to be reviewed by the Senate Intelligence Committee.

"I definitely do have concerns about that news report," Collins told CNN. "I don't know what the evidence is and I think it's really important that we look at the evidence and do so aggressively. We need to follow the evidence wherever it leads."

And Virginia Democratic Sen. Mark Warner, the vice chairman of the committee, told CNN's Erin Burnett Tuesday that "we're going to need to bring (Manafort) in" to discuss connections between the Trump campaign and Russia.

A cloud of suspicion has hung over Trump since the US government confirmed that the Russian government interfered in the presidential election with the aim of hurting Democratic nominee Hillary Clinton and helping Trump. During the campaign, Trump called for a friendlier relationship with Russia, defended Putin from human rights abuse allegations and repeatedly cast doubt on US government conclusions of Russian interference during the campaign and after his election.

Anthony Scaramucci, a hedge fund manager who served on Trump's national finance committee during Manafort's tenure at the helm, said he has "a lot of respect" for Manafort and said he believed Manafort's denial.

"I take Paul at his word that he was working on business interests for Oleg and it wasn't tied to the Russian government," Scaramucci said Wednesday on CNN's "New Day."