In September 2016, the FBI sent an undercover investigator to meet with then-Trump campaign aide George Papadopoulos as part of an investigation into the campaign’s potential ties to Russia, The New York Times reports Thursday. The investigator, who identified herself as Azra Turk, worked alongside a longtime FBI informant to probe Papadopoulos about the connection between the campaign and the Kremlin—but Papadopoulos reportedly grew suspicious, and the investigation did not yield any useful information. The Times notes that the decision to launch an undercover mission underscores what appears to be the FBI’s grave concern that Russia could have been working with the campaign to influence the 2016 election. The move, however, also gives ammunition to President Trump, who has repeatedly claimed that federal officials tried to spy on and undermine his campaign. The alleged FBI activities are now being probed by the DOJ’s inspector general, who is expected to release his findings within the next two months.