House Intelligence Committee Chairman Devin Nunes (R-Calif.) said the Justice Department was citing “spurious national security concerns.” (Bill O'Leary/The Washington Post)

A subpoena that House Intelligence Committee Chairman Devin Nunes (R-Calif.) issued to the Justice Department last week made a broad request for all documents about an individual who people close to the matter say is a sensitive, longtime intelligence source for the CIA and FBI.

The Justice Department has refused to provide the documents. Intelligence officials say the material could jeopardize the source, a U.S. citizen who has aided the special counsel investigation into Russia’s interference in the 2016 campaign.

The subpoena, which was reviewed by The Washington Post, demands “all documents referring or related to the individual referenced in Chairman Nunes’ April 24, 2018 classified letter to Attorney General Sessions.” That is the only material the subpoena seeks.

In an interview Wednesday, Nunes maintained that he was “not interested in any individual.”

“We’re interested in documents that should have been given to us at least last fall,” he said. “That’s what we’re looking for, and any claim to the contrary is wrong, and they know it’s wrong.”

Nunes said that Justice officials have blocked access to specific documents and that the language in the subpoena was an effort to get access to the underlying information.

A Justice Department spokeswoman declined to comment.

On Monday, Nunes told reporters that his request did not seek information about a specific person.

“I’ve never referenced an individual. They did. They did that. I didn’t,” he said, referring to the Justice Department.

Senior intelligence officials alarmed by Nunes’s subpoena warned White House Chief of Staff John F. Kelly last week that the information being sought could not be turned over because it could do serious damage to intelligence-sharing relationships with other countries, The Post reported Tuesday.

Kelly and President Trump sided with the Justice Department, but Nunes and some of his colleagues say they may ultimately win the fight over access to the source’s files.

On Tuesday, senior Justice officials renewed their efforts to fend off his request. During a meeting at the White House, Deputy Attorney General Rod J. Rosenstein discussed the issue with senior officials, according to people familiar with the matter.

Partly as a result of those discussions, the Justice Department has invited Nunes to a classified meeting Thursday in the hopes of resolving the impasse, these people said.

Nunes has said he is seeking information about abuse of the Foreign Intelligence Surveillance Court process. Earlier this week, he said the Justice Department was “citing spurious national security concerns.”

Congress “has a right and duty to get this information and will succeed in getting this information, regardless of whatever fantastic stories the DOJ and FBI spin to The Post,” Nunes said.

He has threatened to seek a contempt vote against Attorney General Jeff Sessions over the issue. Sessions, however, is recused from the matter as part of his larger recusal from special counsel Robert S. Mueller III’s probe and investigations involving the 2016 campaigns.

The battle over access to government files about the secret source is the latest skirmish in a broader dispute between congressional Republicans and the Justice Department concerning investigative documents.

Nunes and Republicans on the committee have repeatedly charged that the Justice Department and FBI have misused the top-secret court process to unfairly investigate Trump supporters.

Rep. Mark Meadows (R-N.C.), a close ally of the president, has threatened to seek the impeachment of Rosenstein if he doesn’t turn over a secret document identifying who is under investigation in the Mueller probe and what possible crimes are being investigated.

Democrats have accused Nunes of running a political smokescreen to protect the president and hobble the Russia probe.

Karoun Demirjian contributed to this report.