The investigators pored over Mr. Steele’s old memos and his contemporaneous notes from meetings with F.B.I. agents in the fall of 2016, according to a person familiar with the investigation. They asked Mr. Steele to explain in detail how he had validated his sources inside Russia, how he communicated with them, and how he decided which of their claims to include in his reports. They spoke at length about Mr. Steele’s work with the F.B.I. on other Russia-related investigations and his contacts with a senior Justice Department official.
The interview was a key step in the investigation by the inspector general, Michael E. Horowitz, into the facts underlying a bitter partisan feud: Did F.B.I. officials do anything wrong in 2016 when they sought to understand the Trump campaign’s links to Russia — including how they used information from Mr. Steele?