A current White House official is “under scrutiny” in the federal investigation into whether Trump campaign associates colluded with Russia to interfere in the U.S. election, the Washington Post reported Friday.

Anonymous sources familiar with the probe told the Post that a “significant person of interest” in the sprawling probe into Russia’s election interference is a senior White House adviser close to President Donald Trump.

“As the president has stated before, a thorough investigation will confirm that there was no collusion between the campaign and any foreign entity,” Press Secretary Sean Spicer told the Post in a statement.

As the Post notes, Trump senior adviser and son-in-law Jared Kushner, Attorney General Jeff Sessions, and Secretary of State Rex Tillerson are among the current administration officials known to have communicated with Russian officials during the campaign.

Former National Security Adviser Michael Flynn was forced out of the administration in February for misleading Vice President Mike Pence about conversations he had with Russian Ambassador Sergey Kislyak about lifting U.S. sanctions. Flynn and former campaign chairman Paul Manafort are central figures in the federal Russia probe, and former Trump campaign foreign policy adviser Carter Page’s ties with Russia are also under investigation.

News that the federal probe had reached officials currently working at 1600 Pennsylvania Avenue dropped shortly after Trump boarded Air Force One to fly to Saudi Arabia for his first-ever international trip.

Though James Comey, the FBI director that Trump fired last week, confirmed the existence of an investigation into Trump’s campaign in March, the Justice Department declined to comment.

“I can’t confirm or deny the existence or non-existence of investigations or targets of investigations,” Justice Department spokeswoman Sarah Isgur Flores told the Post.

Deputy Attorney General Rod Rosenstein on Wednesday announced that the probe would now be helmed by special counsel Robert Mueller, himself a former FBI director.