Story highlights Castro did not offer any proof beyond his suspicion

Castro reaffirmed that it was his "impression" that it would be multiple "people"

Washington (CNN) Democratic Rep. Joaquin Castro predicted Tuesday that the investigations into President Donald Trump's campaign's ties to Russia would lead to imprisonment for some of the key players.

"I wouldn't be surprised after all of this is said and done that some people end up in jail," Castro told CNN's Wolf Blitzer on "The Situation Room."

No hard evidence has been produced demonstrating that Trump or his associates colluded with Russia to interfere in the 2016 presidential election, though the FBI has told Congress at a public hearing that the agency is investigating Trumps' campaign as part of its probe into Russia's interference with the US election last year. Castro did not offer any proof beyond his suspicion.

Castro reaffirmed that it was his "impression" that it would be multiple "people" -- not one person -- who would end up in jail. Asked to elaborate, Castro declined.

"I wish I could, but I can't at this time," Castro, a member of the House intelligence committee, said. "My impression is that people will probably be charged, and I think that people will probably go to jail."