A congressional source said congressional investigators have questioned agencies directly to try to find out what intelligence reports and intercepts Nunes is referring to, but that as of Monday the agencies were still saying they did not know what Nunes was talking about.
In an interview Monday, Nunes told me that he ended up meeting his source on the White House grounds because it was the most convenient secure location with a computer connected to the system that included the reports, which are only distributed within the executive branch.
"Democrats were skeptical, and immediately questioned whether Nunes had obtained his information from the White House itself", NPR's Scott Detrow reports.
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 revelation, first reported by CNN and later confirmed by a spokesman for the chairman, Rep. Devin Nunes, is the latest twist in the odd saga of Nunes' unorthodox actions last week. "I'm not - it just doesn't - so I don't know why he would brief the speaker and then come down here to brief us on something that we would have briefed him on".
Schumer argued on the Senate floor that Nunes would rather protect President Donald Trump than objectively do his job of investigating Russia's role in meddling in the 2016 presidential race.
Mr Nunes has been concerned that Trump associates were captured in "incidental" U.S. surveillance of foreign targets even before Mr Trump made his baseless claims that former president Barack Obama had wiretapped him a year ago. The CIA, FBI, and several locations on Capitol Hill have SCIFs, or Sensitive Compartmented Information Facilities.
The committee Nunes chairs is conducting one of two ongoing congressional investigations into Russia's interference in the 2016 USA election and alleged links between Trump's campaign and the Russian government. "The chairman is extremely concerned by the possible improper unmasking of names of USA citizens, and he began looking into this issue even before President Trump tweeted his assertion that Trump Tower had been wiretapped".
CNN has since reported a similar account of Nunes abruptly leaving a staffer on Tuesday night.
Nunes, whose committee is investigating Russia's interference in the 2016 presidential election, told reporters last Wednesday that he had information that showed Trump and his aides may have been swept up in surveillance of foreign government officials by U.S. spy agencies. Trump has said he feels "somewhat" vindicated by Nunes' findings.
Here's what Nunes actually said last week: "I want to be clear, none of this surveillance was related to Russia, or the investigation of Russian activities or of the Trump team".
The top Democrat on the committee, Rep. Adam Schiff (D-Calif.), called that "bizarre" and "wrong".
A spokesman for Schiff told CNN Monday the California Democrat was declining to comment for now about Nunes' meeting on the White House grounds.
"In our commentary about what had become known as Pizzagate, I made comments about Mr. Alefantis that in hindsight I regret, and for which I apologize to him", Jones said.