Shahram Amiri vanished in 2009 while on a religious pilgrimage to Muslim holy sites in Saudi Arabia, only to reappear a year later in a series of online videos filmed in the U.S. He then walked into the Iranian interests section at the Pakistani Embassy in Washington and demanded to be sent home.

In interviews, Amiri described being kidnapped and held against his will by Saudi and American spies, while U.S. officials said he was to receive millions of dollars for his help in understanding Iran’s contested nuclear program. He was hanged the same week as Tehran executed a group of militants, a year after his country agreed to a landmark accord to limit uranium enrichment in exchange for the lifting of economic sanctions.

Speaking to journalists Sunday, Iranian judiciary spokesman Gholamhosein Mohseni Ejehi said Amiri was convicted of spying charges as he “provided the enemy with vital information of the country.”