Former Trump campaign adviser Carter Page bragged that he was an adviser to the Kremlin in a letter obtained by TIME that raises new questions about the extent of Page’s contacts with the Russian government over the years.

The letter, dated Aug. 25, 2013, was sent by Page to an academic press during a dispute over edits to an unpublished manuscript he had submitted for publication, according to an editor who worked with Page.

“Over the past half year, I have had the privilege to serve as an informal advisor to the staff of the Kremlin in preparation for their Presidency of the G-20 Summit next month, where energy issues will be a prominent point on the agenda,” the letter reads.