A longtime Clinton ally who was once under investigation for a possible violation of the Logan Act may have helped Sidney Blumenthal prepare intelligence memos for Hillary Clinton while she served as secretary of state.

Cody Shearer was the subject of a State Department inspector general probe in 1998 after he allegedly conducted rogue negotiations that "caused temporary diplomatic damage in Bosnia," according to documents obtained by Citizens United through the Freedom of Information Act.

The inspector general found that Shearer, whose ties to the Clintons stretch back to the 1992 election, "may have represented himself as speaking on behalf of the U.S. Department of State" in private conversations about the proposed partitioning of Bosnia — a policy the U.S. publicly opposed.

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More than a decade later, Shearer is entangled in another instance of back-channel information peddling at the State Department.

Shearer assisted Blumenthal and Tyler Drumheller, a former CIA operative, in preparing a series of informal intelligence memos for Clinton as she waded deeper into the Libyan conflict, according to Pro Publica.

The edited tranche of emails published by the State Department in May and June suggest she relied almost exclusively on their guidance to inform her decision-making in the country.

Shearer's sister Brooke first grew close to Clinton during the 1992 presidential election, when she traveled with the former first lady on the campaign trail.

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Shearer's brother-in-law, Strobe Talbott, has been close to the Clintons for decades.

After rising through the ranks of the State Department to become deputy secretary of state, Talbott accepted a position as head of the Brookings Institution.

But it appears he, too, maintained influence at the agency through his connection to Clinton.

When she went looking for a new assistant in June 2009, Clinton turned to Talbott for suggestions on who to hire.

Clinton's emails suggest she and Talbott were in frequent contact and even had "catch-up calls" to provide each other with diplomatic updates.

Talbott's name surfaced in the inspector general documents as having written a letter to his brother-in-law that warned Shearer to "be careful in his actions" in Bosnia during Bill Clinton's presidency.

The records suggest the FBI participated in the probe of Shearer's independent diplomacy.