Former White House chief of staff Reince Priebus was interviewed Friday by special counsel Robert Mueller’s team of investigators, according to multiple reports.

“Mr. Priebus was voluntarily interviewed by Special Counsel Mueller’s team today,” Priebus’s lawyer, William Burck, told Politico.

“He was happy to answer all of their questions.”

Mueller is investigating whether there was collusion between President Trump’s campaign and Russia, and whether Trump obstructed justice, including by firing former FBI Director James Comey.

Priebus’s interview had been expected; he served just six months in the White House before being asked by Trump to step down.