Sen. Harry Reid of Nevada at a news conference on Capitol Hill in Washington in 2014. Reuters

Outgoing Senate Minority Leader Harry Reid compared the gravity of Russia's alleged meddling in the US presidential election to the Watergate scandal and the 9/11 terrorist attacks.

"I think they should have a 9/11-type commission," Reid said during an interview with BuzzFeed on Tuesday night, referring to the panel that examined the details of the September 11, 2001, attacks.

Last week, The New York Times and The Washington Post reported findings from the CIA that suggested Russia tried to help Donald Trump win the presidential election via its hacking of Democratic Party organizations.

A trove of emails and documents from those breaches were published by WikiLeaks.

Reid has been critical of the FBI's response to the hacking, saying the FBI director, James Comey, "ignored" the reports and "single-handedly" cost Democrat Hillary Clinton the election by disclosing the renewal of the investigation into her private email server just two weeks before the election.

"Basically what I said is that it appears to me with all the information that is public which substantiates some of the information that I've received indicates that Comey should take a look at this and that was ignored," Reid said.

Reid joined Clinton's campaign in accusing Comey of costing the Democratic nominee the presidential election with his actions.

"To think that someone who's head of the FBI would abrogate, go against, repudiate a long-standing precedent in the Justice Department that the FBI would not get involved in the last several weeks of an election. Well he got involved not once but several times," Reid said.

"We can look at many different reasons that we lost the Senate and Hillary didn't get elected, but Comey is one of the principals."