WASHINGTON ― President Donald Trump’s nominee to replace fired FBI Director James Comey has rebuked Trump’s repeated claim that investigations into whether his campaign colluded with Russia in the 2016 election are “the greatest Witch Hunt in political history.”

Christopher Wray, Trump’s pick to replace Comey, also suggested that the president’s eldest son acted improperly last year when he met with a Russian government-linked lawyer after being promised damaging information about Democratic presidential nominee Hillary Clinton. That meeting is likely the clearest indication so far that the Trump campaign may have colluded with Russia.

In tweets defending his son on Wednesday, Trump said his son was “innocent” and called news about the meeting, which Trump Jr. confirmed by releasing emails documenting it, a “witch hunt.”

“I do not consider Director Mueller to be on a witch hunt,” Wray said Wednesday, when asked during his Senate confirmation hearing about the independent probe led by special counsel Robert Mueller.

Sen. Lindsey Graham (R-S.C.), reading directly from Donald Trump Jr.’s emails documenting the existence of the meeting, asked Wray if Trump Jr. should have agreed to the meeting.

Wray demurred, saying that he had not been focused on the story. But after Graham pressed him, he affirmed that “the FBI would want to know” of such interactions.

“Any threat or effort to interfere with our election by any nation state or any non-state actor is the kind of thing the FBI would want to know,” he said.

Mueller’s investigation is also reportedly focused on whether Trump obstructed justice. Trump abruptly fired Comey in May, amid the FBI’s investigation into Trump’s campaign.

Last month, Comey testified before the Senate that he believes he was fired because of the Russia investigation. He also testified that Trump asked him for loyalty and to end his investigation into former national security adviser Mike Flynn, who resigned after lying to Trump administration officials about his interactions with Russian officials.