Their private assessment contradicts President Donald Trump's allegations that former Obama national security adviser Susan Rice broke the law by requesting the "unmasking" of US individuals' identities. Trump had claimed the matter was a "massive story."
However, over the last week, several members and staff of the House and Senate intelligence committees have reviewed intelligence reports related to those requests at NSA headquarters in Fort Meade, Maryland.
One congressional intelligence source described the requests made by Rice as "normal and appropriate" for officials who serve in that role to the president.
And another source said there's "absolutely" no smoking gun in the reports, urging the White House to declassify them to make clear there was nothing alarming in the documents.
Still, some members of Congress continue to have concerns about the justification given for the unmasking requests and the standards for the intelligence community to grant such requests, which reveal the private data of US persons mentioned in intelligence reports based on routine intelligence collection aimed at foreign nationals.
Such collection regularly targets officials and nationals from Russia, Taiwan, Israel and other countries.
The lawmakers' assessment comes after Trump, in a New York Times interview last week, accused Rice of breaking the law.
Trump has not revealed which intelligence reports he is relying on to make his charge that Rice may have acted illegally.
"I think it's going to be the biggest story," Trump said. "It's such an important story for our country and the world." He also called it "truly one of the big stories of our time."
Asked by the Times if he believed Rice's actions were criminal Trump responded, "Do I think? Yes, I think."
Sebastian Gorka, a Trump foreign policy aide, cast Rice's actions as worse than the Watergate scandal that felled President Richard Nixon in an interview with pro-Trump Fox News host Sean Hannity.
"Losing 14 minutes of audiotape in comparison to this is a little spat in the sandbox in the kindergarten," Gorka said.
Rice defended her actions last week on MSNBC, saying her requests were "absolutely not for any political purposes, to spy, or anything."
"There were occasions when I would receive a report in which a US person was referred to -- name not provided, just a US person -- and sometimes in that context, in order to understand the importance of the report, and assess its significance, it was necessary to find out, or request the information as to who the US official was," Rice said.
"The notion that some people are trying to suggest, is that by asking for the identity of a person is leaking it, is unequivocally false," she said. "There is no connection between unmasking and leaking."
Rice is among the list of witnesses that House and Senate Intelligence officials want to interview as part of its probe into Russian attempts to meddle with the US elections. House Democrats and Republicans on the Intelligence Committee are near agreement on the list of witnesses to interview, with the GOP mostly focusing on people who may have leaked classified information and the Democrats hoping to question Trump associates who may have ties to Russia.
But the House review has been thrown into turmoil after Nunes last month expressed alarm about the unmasking of US persons, including Trump advisors, caught up in incidental collection. He reviewed the documents on White House grounds with the help of White House officials, despite House Speaker Paul Ryan saying Nunes informed him that the information came from a "whistleblower."
Critics said Nunes appeared to be giving political cover to Trump in the aftermath of the president's unsubstantiated tweet last month that Obama ordered wiretaps of Trump Tower to spy on him during the campaign.
Nunes' office has not responded to CNN's request for comment.
Nunes last week abruptly recused himself temporarily from the Russia investigation as the House Ethics Committee announced it is investigating whether he revealed classified materials, but he is still serving as chairman of the panel.