House Intel chair was on the White House grounds the day before he dropped Trump surveillance bombshell

House Intelligence Chair Devin Nunes was on White House grounds the day before he briefed President Donald Trump on intelligence he said showed the president and his advisers may have had their communications "incidentally collected" by the intelligence community during the transition period.

Speaking to CNN, Nunes, a member of Trump's transition team, confirmed he was on the White House grounds, which includes buildings such as the Eisenhower Executive Office Building, but was not in the White House itself. He added that the Trump administration was not aware he was there.

The purpose of his trip to the White House grounds was, he said, to view the information he obtained in a secure setting.

In a statement, the California congressman's office added that Nunes was investigating "the possible improper unmasking of names of U.S. citizens" before Trump made his unfounded Twitter claim in early March that Trump Tower had been wiretapped by President Barack Obama. Nunes has said no evidence supports the president's claim.

Nunes caused a stir last week when he told the press and Trump that he had seen reports which showed the intelligence community "incidentally collected" information about Trump and his team during the transition period. He said the collection occurred on "numerous occasions" and was not related to the FBI's investigation into Russian meddling in last year's presidential election, making it okay for him to share with the president.

Nunes was asked if the information he shared came directly from the White House, which he would not confirm or deny, stressing that "we have to keep our sources and methods here very, very quiet." The House intelligence chair said his decision to brief Trump was a "judgment call."

The episode stunned many, including members of the intelligence committee, who were not briefed about the information before Nunes went to the press and to Trump.

The ranking Democrat on the committee, Adam Schiff of California, blasted Nunes for the move, saying it compromised their committee's investigation.

"At this point, the only people who do know are the chairman and the president," Schiff told NPR. "And given that the president's associates are the subject in part of the investigation, that's wholly inappropriate, and, unfortunately, I think it really impugns the credibility of the chairman in terms of his ability to conduct an independent investigation."