(CNN) US intelligence and law enforcement agencies have been puzzled by House Intelligence Committee Chairman Devin Nunes' apparent efforts in the past week to come to the rescue of President Donald Trump over his Tweeted claim that President Barack Obama wiretapped him at Trump Tower.

Nunes, along with FBI Director James Comey and NSA Director Mike Rogers, have said Trump's claim isn't true . But Nunes has also said that the President's claim shouldn't be taken literally and said the new information he received last week raised questions about surveillance.

While Nunes didn't give much clarity on what he means when he was interviewed by CNN's Wolf Blitzer on Monday , one possibility is this: Suspicion in the US intelligence and law enforcement community has centered on the likelihood that Trump transition members might have been caught up in surveillance of foreign leaders and their staff.

One GOP source who has been briefed on what Nunes has seen said these conversations were "primarily among diplomats" and was "almost like the kind of trivia you would pick up" in gossipy conversations about "Trump and what he was doing" during the transition, such as "where he was having dinner."

He further added that it was "easy to identify who they were talking about."

While the source said these conversations reveal "nothing salacious," he also adds that there was "no need to pass this on" to anyone in the Obama administration.

Nunes' source, according to the Republican official, is "currently inside the intelligence community."

Nunes has not described the information he saw in any detail beyond saying it did not have anything to do with Russia, said that he was "bothered" by the sharing of the information. He noted the information was circulated "widely through the executive branch" in November, December and January, or the transition period.

"As somebody who supports our national security apparatus, it bothered me that this level of information would be included in intelligence reports, because it just wasn't necessary, from my point of view -- legal or not," Nunes said during his interview with Blitzer.

Pressed by Blitzer on whether names were illegally unmasked, Nunes said "for the most part, they were masked," and then said, "but like I said, there was additional unmasking."

Nunes said even if the names were masked "it was pretty clear who they were talking about, what the reports were referring to."

US intelligence routinely monitors communications of foreign leaders and staff of certain countries, including Israel, China, Taiwan, and Russia, according to current and former officials.

Those are among the countries that Trump transition team members are known to have held calls with following the US election.

If those foreign officials later discussed their interactions with the Trump team, US intelligence likely would be monitoring, US officials said. And if US intelligence analysts find anything of value as foreign intelligence, they often summarize such communications in intelligence reports. But intelligence reports would remove any name of an American mentioned when the report is circulated so anyone in the executive branch authorized to read the reports would not know the names.

For now, the current White House is referring questions about the information to Nunes.