WHITE HOUSE - Members of Congress looking into Russian interference in last year's presidential election have been invited to the White House to examine relevant secret documents.

Lawmakers confirmed such a letter was received by the Senate and House intelligence committees Thursday, a move that White House Press Secretary Sean Spicer defended as "doing the responsible thing." The documents to be reviewed apparently were the basis for controversial comments by Congressman Devin Nunes that were seen by some as bolstering President Donald Trump's charge that his campaign team was "wiretapped" last year on the orders of former President Barack Obama.

White House Offers to Show Lawmakers 'Wiretap Documents'

Even as he announced the offer to bring relevant lawmakers to the White House to review secret information, Spicer deflected reporters' questions Thursday about Nunes' unusual visit to the White House grounds more than a week ago to see the intelligence reports.

White House Offers to Show Lawmakers 'Wiretap Documents'

Spicer answered "no" when asked whether he knew who invited Nunes to the White House complex on March 21, and he steered clear of confirming or denying details of a news report that named two officials who allegedly gave Nunes intelligence information.

White House Offers to Show Lawmakers 'Wiretap Documents'

The posted a story online just prior to Spicer's briefing Thursday naming two White House officials who it said helped provide Nunes with highly classified intelligence reports indicating that Trump and his associates were swept up in surveillance of foreign officials by U.S. spy agencies.

The press secretary has repeatedly criticized White House correspondents for focusing their questions on process — essentially, who told what to whom — rather than substance, the details of the information that Nunes received.

"Process here is the whole story," Ken Gude, an analyst who specializes in national security issues, told VOA. "The White House basically used Nunes here, the chairman of the House Intelligence Committee, to filter, to 'launder' some of the information."

Gude, a senior fellow at the Center for American Progress, said it appeared that White House officials fed information to Nunes to give Trump "some cover." The president had been widely criticized following his allegation on March 4 that Obama ordered electronic surveillance against Trump's campaign team — an assertion that has been repeatedly denied by senior U.S. intelligence and law enforcement officials.

The said the two officials who provided Nunes with highly classified intelligence reports were former Defense Intelligence Agency official Ezra Cohen-Watnick, now the senior director for intelligence at the National Security Council, and Michael Ellis, a former House Intelligence Committee staffer who now works on national security issues at the White House counsel's office.

Spicer declined to discuss the report, saying, "I'm not going to get into further details on this."

Sorry, but your browser cannot support embedded video of this type, you can to view it offline.

A government investigation of Russian meddling during the U.S. presidential campaign last year has stayed in the headlines for weeks, particularly since Trump tweeted his belief that his headquarters in New York City had been "wiretapped." U.S. intelligence officials have said there were no surveillance orders from Obama aimed at Trump, and that no such order could come from the president, under domestic intelligence-gathering procedures in place for years.

Nunes, a former adviser to Trump's presidential transition team, subsequently said that he did not believe Trump Tower had been bugged, but that the campaign team's communications could have been caught up in a wider investigation that inadvertently targeted the transition office.

On March 22, a day after his mysterious nighttime visit to the White House grounds — a large area that incorporates the adjacent Executive Office Building, which is the headquarters of the National Security Council — Nunes told reporters he had been shown intelligence indicating communications involving Trump and/or his associates had been captured in a legal "but inappropriate" manner.

Nunes has been mum on who at the White House showed him the materials.

His behavior has been strongly criticized by Democrats, and the party's ranking member on the House Intelligence Committee, Adam Schiff, has called on Nunes to step down from his chairman's post.

"Why all the cloak and dagger stuff? That's something we need to get to the bottom of," Schiff told reporters Thursday.