Information acquired by the Federal Bureau of Investigation (FBI) suggests that President Donald Trump's associates possibly communicated with suspected Russian operatives to coordinate the release of information that would damage Hillary Clinton's campaign.
CNN on Thursday (March 23) cited US officials as saying that the FBI is now reviewing that information.
The information includes human intelligence, records of travel, business and phone calls, and accounts of meetings made in person.
However, the officials cautioned that the information was not conclusive and investigations are ongoing.
FBI Director James Comey had on Monday (March 20) publicly challenged President Trump, confirming that the FBI had launched a criminal investigation into any collusion between Russia and Trump's campaign.
The committee is investigating accusations that Russia tried to influence the election mostly by hacking Democratic operatives' e-mails and releasing embarrassing information. Russia denies the allegations.
Mr Comey had said that Moscow has long been opposed to Trump's election rival, former secretary of state Clinton.
"Putin hated Secretary Clinton so much that the flip side of that coin was he had a clear preference for the person running against the person he hated so much," he said.