(CNN)The Justice Department has opened an investigation into allegations surrounding a former Senate Intelligence Committee staffer's unauthorized disclosure of information, prompting the Senate panel to share records related to the federal probe.
Justice Department investigating ex-Senate Intel staffer over allegations of improperly disclosing information
The identity of the former committee aide under investigation has not been disclosed, but sources say prosecutors appear to be preparing charges soon against the individual.
The information that was improperly disclosed may have been classified, as much of the committee's work is with documents that are sensitive or classified.
In an unusual move, the Senate quietly passed a resolution Wednesday evening authorizing the Senate panel to provide the Justice Department with documents in connection with the investigation. The records are related to a Justice Department investigation into "allegations of the unauthorized disclosure of information by a former employee of the Committee," according to a description of the resolution printed in the congressional record.
In a joint statement Wednesday, Senate Intelligence Chairman Richard Burr of North Carolina and Vice Chairman Mark Warner of Virginia said the committee was cooperating with the Justice Department investigation.
Burr noted on Thursday that the situation was uncommon.
"I think the United States Senate responds to requests from the Department of Justice when they're made -- they're not frequently made," he said.
The senators leading the panel have been tight-lipped about the investigation, referring comment to the Justice Department. Senators on the committee were briefed on the matter earlier this week.
"We can't get into personnel issues," Burr said Thursday when asked about the allegations. "Any action you'd have to talk to the Department of Justice about."
Warner, the top Democrat on the panel, would not discuss whether charges would be brought imminently. But he emphasized he could not discuss the matter "today."
CLARIFICATION: This story has been updated to clarify that it's not certain that the disclosed information was classified.