Treasury Secretary Steven Mnuchin followed internal protocols when he refused to give President Trump’s tax returns to Congress, Treasury’s office of inspector general found in a report obtained by The Washington Post on Friday ahead of its public release.

Richard K. Delmar, deputy inspector general of the Department of Treasury, wrote in a letter to House Democrats that Mnuchin “properly” processed the demands for Trump’s returns and followed the guidance of the Department of Justice’s Office of Legal Counsel. Lawyers for the legal counsel’s office wrote in a June 2019 opinion that House Democrats’ demands for Trump’s return should be denied because they did not serve a legitimate “legislative purpose.”

“The core of our inquiry is that the [Treasury] Department processed the request properly, that it sought legal guidance from the Department of Justice’s Office of Legal Counsel, determined that it was bound by that office’s advice, and based on that advice determined not to provide the returns and tax information sought,” Delmar’s one-page letter states.