Christopher Steele refused to hand over to U.S. Attorney John Durham notes the former MI6 agent took of meetings with the FBI in July and October 2016, as the now-special counsel scrutinizes whether the bureau improperly disclosed classified information to the former MI6 agent, according to a report.

An article published by Politico on Saturday stated that Durham, appointed by Attorney General William Barr to investigate wrongdoing by the Trump-Russia investigators, “has been searching for evidence that FBI agents mishandled classified information” and “specifically zeroed in on records belonging to” Steele, citing “court records and people familiar with his investigation.” Durham is reportedly focusing on notes that Steele took of his FBI meetings in early July 2016 at his Orbis Business Intelligence office in London and in early October in Rome. Those notes were evidence in a defamation lawsuit brought against Steele by owners of the Russian Alfa Bank, in which Steele testified this year.