House intel chair was on White House grounds day before briefing Trump on alleged surveillance It's not clear why Rep. Devin Nunes chose to go to White House grounds.

 -- House Intelligence Committee Chair Devin Nunes, R-California, who is leading a congressional investigation into Russian meddling in the 2016 campaign and alleged contacts with the Trump campaign, went to White House grounds last week to meet a source at a secure location to view information regarding possible "incidental" surveillance of Trump associates by the U.S. intelligence community, his office confirmed to ABC News.

The visit came one day before Nunes made a surprise public announcement about the documents before sharing them with other members of the House Intelligence Committee and then proceeded to the White House to brief President Donald Trump in person.

"Chairman Nunes met with his source at the White House grounds in order to have proximity to a secure location where he could view the information provided by the source. The chairman is extremely concerned by the possible improper unmasking of names of U.S. citizens, and he began looking into this issue even before President Trump tweeted his assertion that Trump Tower had been wiretapped," Nunes' spokesperson Jack Langer said in a statement provided to ABC News.

The committee Nunes chairs is conducting one of two ongoing congressional investigations into Russia's interference in the 2016 U.S. election and alleged links between Trump's campaign and the Russian government. The committee's ranking member Rep. Adam Schiff, D-California, had no comment.

On Friday, Nunes backtracked on some of the claims he said earlier in the week regarding the documents he reviewed.

When asked if he could clarify whether Trump or his associates were monitored or simply mentioned in the intelligence reports, Nunes said he won't know until he receives all the documentation.

The National Security Agency was supposed to deliver documents to the intelligence committee on Friday, but it's unclear whether that has happened yet.

It's also not clear why Nunes chose to go to White House grounds when there is a Sensitive Compartmented Information Facility (SCIF) on Capitol Hill to review sensitive information.

Nunes has not disclosed where he got the information from, not even to other members on the House Intelligence Committee.

White House press secretary Sean Spicer on Friday would not rule out that it came from the White House.