Former FBI Director James Comey said Thursday he doesn’t know “what the heck” Attorney General William Barr was “talking about” when Barr said he believed the Justice Department was “spying” on the Trump campaign in 2016.

“I really don’t know what he’s talking about when he talks about spying on the campaign,” Comey said in response to a question at the Hewlett Foundation’s Verify Conference in San Francisco, where Comey was a speaker. (See the clip above.)

“It’s concerning because the FBI and the Department of Justice conduct court-ordered electronic surveillance. I have never thought of that as spying.” Has the attorney general “come to the belief that that should be called spying?” Comey said. “Wow. That’s going to require a whole lot of conversations inside the Department of Justice.”

Comey also said he was unaware of any court-ordered surveillance “aimed at the Trump campaign.”

He added that Barr’s career should have earned him a “presumption that he will be one of the rare Cabinet members who will stand up for things like truth and facts and institutional values.”

But Comey also conceded that “language like this” — referring to the spying accusation — undercuts that presumption. “And because I don’t know what the heck he’s talking about, that’s all I can say,” he concluded, NBC News reported.

Comey was in charge of the FBI when the agency launched an investigation into Russian interference in the presidential election — and possible Donald Trump campaign cooperation. The investigation was reportedly triggered July 2016 in part because of a tip from the Australian government that Trump campaign adviser George Papadopoulos had earlier boasted that he had been told Russia had stolen emails damaging to Democratic rival Hillary Clinton. Trump fired Comey in May 2017.

Barr told a Senate subcommittee on Wednesday that he believed government “spying” on the campaign “did occur” and that it raised questions for him about inappropriate surveillance. He offered the perspective — though presented no evidence for it — as justification for launching a probe into the origins of the investigation into Russian interference.

“I think spying on a political campaign is a big deal,” said Barr. “I think spying did occur. But the question is whether it was ... adequately predicated.”