Washington (CNN) President Donald Trump "has got a real problem" after the latest revelations regarding White House counsel Don McGahn's interviews with special counsel investigators, according to John Dean, who served in the same role for President Richard Nixon.

"I think that's a lot of testimony, that's a lot of visiting, and that's just the bottom of what they know," Dean said Monday in an interview on CNN's "The Lead with Jake Tapper." "It could well have been much more than that. It appears to have been ongoing. So, I think Trump has got a real problem here. And I'm not sure how he's going to handle it."

On Sunday, Trump referenced Dean in a Twitter post lashing out at a Times report from the day before, claiming it falsely said McGahn must be "a John Dean type 'RAT" for giving hours of testimony to the special counsel, and adding that he "allowed him and all others to testify," referring to McGahn.

Dean is known for his cooperation with prosecutors during the Watergate investigation after serving as White House counsel for Nixon.

Read More