(CNN) "Off the map." That's how a former CIA director on Saturday described the notion of Jared Kushner, a top aide to his father-in-law, President Donald Trump, setting up a secret communications channel between Washington and the Kremlin.

Such a back channel would be unprecedented, said retired four-star Gen. Michael Hayden, who also once headed the National Security Agency.

"This is off the map," Hayden told CNN's Michael Smerconish . "I know of no other experience like this in our history, certainly within my life experience."

Kushner spoke in December with the Russian ambassador about creating a secret communications channel with the Kremlin, a source with knowledge of the matter confirmed to CNN. Kushner is under investigation as part of the FBI probe into Russian meddling in the 2016 election.

Several Trump administration officials declined Saturday to comment on the reports.

Asked by Smerconish if he thought such an inquiry by Kushner would have been nefarious or naïve, Hayden said the latter.

"Right now, I'm going with naivete, and that's not particularly comforting," he said. "What manner of ignorance, chaos, hubris, suspicion, contempt would you have to have to think that doing this with the Russian ambassador was a good or an appropriate idea?"

Kushner at the time of the alleged conversation was acting in an official capacity on behalf of the incoming administration and was benefiting from an interim clearance.

Aside from being an example of potential collusion with the Russians, such actions by Kushner would indicate a degree of contempt and suspicion for the Obama administration that Hayden found hard to fathom, he told Smerconish.

"It says an awful lot about the campaign," Hayden said. "It says an awful lot about us as a society that we could actually harbor those kinds of feelings that the organs of the state would be used by my predecessor to come after me or to intercept my communications or to disrupt my administration in a way that made it seem legitimate to me to use the secure communications facilities of a foreign power."