The former Trump attorney, who was previously sentenced to three years in prison for tax fraud and the payment of hush-money to two women with whom the president allegedly had affairs, testified in the House Oversight Committee on Wednesday.

Michael Cohen said that he has no direct evidence that Trump or his campaign colluded with Russia during the 2016 election.

"Questions have been raised about whether I know of direct evidence that Mr. Trump or his campaign colluded with Russia. I do not. I want to be clear," Cohen said in his opening statement.

"But I have my suspicions," he added, saying there were "so many dots that all seem to lead" to the Kremlin.

Cohen has yet to serve out his prison sentence, and is cooperating with FBI Special Counsel Robert Mueller's long-running probe into possible collusion between the Trump campaign and Moscow.

Asked by Congresswoman Debbie Wasserman Schultz (D-Florida) whether Trump would stoop to colluding "with a foreign power to win the presidency," Cohen said the question "calls on so much speculation," adding that "it would be unfair…to give you an answer to that."

"As I stated in my earlier testimony, I wouldn't use the word colluding," Cohen said. "Was there something odd about back-and-forth praise with [Russian President Vladimir] Putin? Yes. But I'm not really sure that I can answer that question in terms of collusion," he said.

Schultz resigned from her post as head of the Democratic National Committee in 2016 after WikiLeaks dumped a series of emails revealing evidence of collusion between the Clinton campaign and the Democratic Party to squash the campaign of Clinton's Democratic rival, Bernie Sanders. Clinton and the Democrats later went on to allege that WikiLeaks had received the leaked emails from Kremlin-backed Russian hackers, a charge they have yet to substantiate.

During his testimony Wednesday, Cohen distanced himself from the president, depicting Trump as a "racist" and a "conman," and claiming that Trump knew that Republican operative Roger Stone was coordinating with WikiLeaks to release the damaging DNC emails. Stone has repeatedly denied the charges. President Trump himself has called the entire Russiagate narrative a "witch hunt" against him.

Robert Mueller formed the Special Council Investigation in 2017 to probe claims of Russian attempts to meddling in the 2016 US presidential race, and has served subpoenas and indictments against multiple Trump associates, including former campaign chairman Paul Manfort, former National Security Adviser Michael Flynn and ex-Trump attorney Michael Cohen. While finding evidence of corruption, financial crimes and other wrongdoing, the probe has yet to find any evidence of collusion between Trump and the Kremlin.

Russian officials have repeatedly denied interfering in the 2016 race, characterising the meddling claims as an attempt to explain away Hillary Clinton's unexpected and humiliating defeat to Trump, and pointing out that the numerous Russiagate investigations, whether by the media, by Congress or by Mueller, have yet to provide any proof to back up collusion claims, over two years into Trump's term in office.