(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.

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.

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