Former Deputy Attorney General Sally Yates declined to say any Presidential candidates had their communications intercepted by American intelligence during the 2016 campaign Monday.

“Was there any incidental collection, where our intelligence community collects information involving a presidential candidate, on either side of the aisle, during 2015 or 2016,” Sen. Lindsay Graham’s (R-SC) asked Yates and fellow witness before the Senate Judiciary Committee’s Subcommittee on Crime and Terrorism, former Director of National Intelligence James Clapper.

Clapper answered that he was not aware of any such collection, but Yates was less categorical. She declined to answer, noting that FBI Director James Comey had done so to the same question and that doing so comported to DOJ policy.

“Again you should not draw from that that my answer is yes, but rather that the answer would require me to reveal classified information,” Yates told the Committee.

President Donald Trump made headlines with his March allegation that he and his staff had been “wiretapped” at Trump Tower. Senator Graham has expressed his grave concern of the implications if Trump himself had been recorded in intelligence operations conducted under the Obama administration.

Graham phrased his initial question to refer also to presidential staff and campaign members, but narrowed his focus the candidates themselves before the witnesses gave their answers.

Monday’s hearing was held to discuss the investigation conducted by four U.S. intelligence agencies, and ordered in December by former President Barack Obama, into Russia’s attempts to influence the elections. The finding which led to the resignation of National Security Advisor and Trump campaign confidant General Michael Flynn were a major focus of the hearing.