An email chain in which Hillary Clinton and her top aides discussed controversial talking points was withheld from the House Select Committee on Benghazi by State Department officials, raising further questions about the agency's cooperation with the congressional investigation.

The pair of undisclosed emails came to light in a Freedom of Information Act lawsuit filed by the conservative nonprofit Judicial Watch after the State Department told the group it planned to withhold the records. The select committee confirmed to the Washington Examiner that the records had not been given to Congress.

Tom Fitton, president of Judicial Watch, said the agency's refusal to release the two emails to either his group or the select committee suggests information about Clinton's involvement is being covered up.

"There is something here that is scandalous, otherwise they would have released it," Fitton said.

State Department officials argued last week in court filings that the email exchange was protected under FOIA exemptions that allow the government to withhold records produced during a decision-making process.

"Their explanation doesn't hold water," Fitton said. "This deliberative process they're asserting is not being made in good faith. There's a cover-up going on."

The three-page document in question involves two emails sent between Jacob Sullivan, Clinton's then- deputy chief of staff and a current staffer on her campaign, Cheryl Mills, her chief of staff at the time, and Philippe Reines, her spokesperson at State.

"The bodies of the messages consist of drafts, composed by advisors to former Secretary Clinton, of a proposed future communication from the former Secretary to a member of the U.S. Senate concerning various issues related to the attacks of September 11, 2012 in Benghazi," the State Department said in court documents.

The select committee has not received any email records for Reines, and only a few for Mills, Sullivan and Ambassador Susan Rice.

Talking points that blamed the Benghazi terror attack on a spontaneous reaction to a YouTube clip in the days after the 2012 raid have since been debunked, sparking widespread interest into the internal discussions that prompted officials to promote the false narrative.

Chairman Trey Gowdy has repeatedly raised concerns that the State Department is stonewalling requests for the records of Clinton's top aides.

The agency's production last month of 3,600 documents to the committee did little to stem criticism from its Republican members after it became clear that many of the records were duplicates and that several had been withheld.

Last week, Gowdy revealed that the bulk of those documents were actually press clippings that shed little light on the State Department's handling of Benghazi.

The select committee has twice asked the State Department to describe what they have withheld and why in response to the three separate instances in which the agency declined to produce Benghazi-related documents to Congress.

"They've been obstructed by the State Department for years on this issue, and there's been no accountability and no downside to the State Department making a mockery of the congressional oversight process," Fitton said of congressional attempts to extract documents from the agency.