Washington (CNN) The former director of the CIA suggested Wednesday that President Donald Trump is withholding criticism of Russian President Vladimir Putin because the Russians might have compromising personal information on Trump.

"I think he is afraid of the President of Russia," John Brennan said of Trump in an interview on MSNBC's "Morning Joe."

Asked why, Brennan said, "The Russians could have something on him personally that they could always roll out and make his life more difficult."

The former intelligence chief said the Russians "have had long experience with Mr. Trump and may have things that they could expose and reveal," adding that "perhaps" Moscow has personal information on Trump.

"But the fact that (Trump) has had this fawning attitude toward Mr. Putin, has not said anything negative about him, I think continues to say to me that he does have something to fear and something very serious to fear," argued Brennan, who was CIA director under President Barack Obama but served in the agency for decades.

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