Rep. Elijah Cummings, the top Democrat on the House Select Committee on Benghazi, slammed the Republican chairman late Monday for his refusal to investigate the source of a leak about Hillary Clinton's private emails.
The Maryland Democrat also criticized South Carolina Rep. Trey Gowdy for neglecting to interview a single witness from the Department of Defense since the select committee was created.
Gowdy downplayed the leak in a letter to Cummings that instead called on the minority to join Republicans on the committee and others in pressuring Clinton to relinquish the private server that housed her government emails.
The push to review Clinton's server grew stronger after a Benghazi witness, Sidney Blumenthal, provided emails to Congress that Clinton had never given to the State Department.
Blumenthal's previously undisclosed records indicated Clinton had not turned over all her work-related emails, as she claimed to have done during a March press conference.
Democrats and Republicans on the select committee have grown increasingly bitter in their public exchanges as Clinton's candidacy has injected a fresh dose of partisanship into the Benghazi probe.
Last week, the committee sparred internally over whether members would hold a vote on the release of transcripts from the Blumenthal deposition.
Democrats have argued that releasing the transcripts would provide context to the dozens of Blumenthal emails the committee published last month. Republicans have countered that doing so may discourage future witnesses from being candid behind closed doors.
Cummings pointed to past Benghazi-related leaks Monday as evidence that Republicans on the several committees that have investigated the 2012 terror attack have fed misleading information to reporters in an effort to twist the Benghazi narrative.
He noted an instance in 2013 in which he said ABC News and the Weekly Standard received from an anonymous source "an inaccurate characterization of an email from National Security Council official Ben Rhodes, including words that simply were not there, in order to misrepresent the White House's role in editing the intelligence community's talking points."
Cummings also highlighted a 2013 Fox News appearance by Rep. Darrell Issa, then-chairman of the House Committee on Oversight and Government Reform, during which he said Issa attributed to Clinton a signed State Department cable denying a request for security, when the cable simply bore a "pro-forma" stamp of her signature.
Gowdy criticized the minority Monday for their reluctance to help congressional investigators obtain documents that would move the probe forward. Several of the committee's records requests have languished in government agencies for months.
The State Department handed over 3,600 documents to the select committee June 30.
However, many of the records were duplicates, and the production came days after Gowdy threatened to summon Secretary of State John Kerry for the agency's failure to provide records involving 10 top Clinton aides.
The documents given to the committee last week included emails sent by Ambassador Susan Rice, chief of staff Cheryl Mills and her deputy Jake Sullivan.
The South Carolina Republican has announced his plans to bring Mills, Sullivan and deputy chief of staff Huma Abedin before the committee to testify about their role in the State Department's handling of the Benghazi attack.