The Washington Examiner's Byron York reported last month that congressional investigators were “looking into a possible Obama State Department role in the collection and dissemination” of the dossier compiled by Steele, who gave his preliminary findings to the FBI in the summer of 2016. But in television interviews over the weekend, Nunes would not elaborate on how his nearly year-long investigation into Steele and the dossier came to implicate the State Department.

A letter released Monday by Republican Senators Chuck Grassley and Lindsey Graham offers an important clue.

In the heavily redacted, declassified version of the letter, which outlined why Graham and Grassley asked the Justice Department to consider opening a criminal investigation into Steele’s communications with the FBI, the senators allege that “Clinton associates” were “feeding Mr. Steele accusations” against the Trump campaign, thereby calling into question Steele’s credibility as a neutral source.

Two sources familiar with the matter, who requested anonymity because they were not authorized to speak to the press, told me the redacted portions of the letter refer to the information compiled by Shearer—for the first time revealing some of the key details that were redacted in the original letter. Shearer’s information was passed to Steele by Winer. Winer, a friend of Steele’s, was then serving as the special envoy for Libya, and had previously passed Steele’s Russia and Ukraine reports along to the State Department’s Europe bureau between 2014 and 2016. Shearer, Blumenthal, and Winer did not immediately respond to requests for comment.

The Grassley-Graham letter says that Steele wrote a “memorandum” to the FBI in October 2016 describing how he had obtained a document based on intelligence received about Trump from “a foreign sub-source.” “One memorandum by Mr. Steele that was not published by BuzzFeed is dated October 19, 2016,” the letter says. The two sources confirmed that the document in question was the memorandum written by Shearer. The letter continues:

The report alleges [redacted] as well as [redacted]. Mr. Steele’s memorandum states that his company ‘received this report from [redacted] U.S. State Department,’ that the report was the second in a series, and that the report was information that came from a foreign sub-source who ‘is in touch with [redacted], a contact of [redacted], a friend of the Clintons, who passed it to [redacted].’ It is troubling enough that the Clinton Campaign funded Mr. Steele’s work, but that these Clinton associates were contemporaneously feeding Mr. Steele allegations raises additional concerns about his credibility.

According to a source familiar with the matter, however, Steele’s “memorandum” was actually a handwritten note on a copy of Shearer’s report that outlined its origin—the “foreign sub-source” who had been in touch with Shearer. The note identified Shearer as a contact of Sidney Blumenthal’s, a longtime associate of the Clintons. It also explained that Steele had obtained the document via Winer, who had gotten it from Shearer.