Rep. Jason Chaffetz, the House oversight committee chair, questioned the motives behind the Justice Department's appointment of a special prosecutor on Wednesday to oversee the FBI's investigation into the Trump campaign's ties to Russia.

"I think they're feeling the political heat," Chaffetz, a Utah Republican, told Fox News' Tucker Carlson on Wednesday evening. "Maybe they're watching a little too much television and read too many newspapers and whatnot."

"I have not seen any evidence of actual collusion," Chaffetz said. "Where is the actual crime that they think they need a special prosecutor to prosecute? I just haven't seen it."

Chaffetz also took note of the Department of Justice's quick action Wednesday.

"I'm very surprised by it. No heads-up," Chaffetz said. "I at least read online that the White House only got about 30 minutes heads up."

Robert Mueller. cvrcak1 via Flikr

The DOJ appointed former FBI Director Robert Mueller to oversee the FBI's investigation into potential ties between the Trump campaign and Russian officials and whether the Trump campaign colluded with Russia to meddle in the 2016 US election.

The appointment, made by Deputy Attorney General Rod Rosenstein, comes amid a bipartisan outcry for a special counsel after a string of revelatory news reports rocked the White House in recent weeks.

"My decision is not a finding that crimes have been committed or that any prosecution is warranted," Rosenstein said in a statement. "I have made no such determination. What I have determined is that based upon the unique circumstances, the public interest requires me to place this investigation under the authority of a person who exercises a degree of independence from the normal chain of command."

Chaffetz said the investigation "could go on for years."

"And there could be long periods of just silence," he said. "And what I worry is that the Democrats are going to politically exploit this on a daily drumbeat, making up theories, making up stories ... when you don't have the definitive word from somebody who's going to be essentially silent.

"Does that seep out? At what point does that let off," Chaffetz continued. "I physically don't know exactly where those lanes are."

Chaffetz also questioned the validity of memos James Comey was said to have recorded when he was FBI director. The New York Times on Tuesday reported that Comey recorded a memo in February saying Trump had asked him to drop the bureau's investigation of ousted national security adviser Michael Flynn. Trump fired Comey last Tuesday. "I'm not even sure that these memos even exist," Chaffetz said. "I don't even know that they're real."

"You can't run an investigation on anonymous sources in The New York Times," he said. "That's just not conclusive evidence."

Watch the interview here »