A Canadian-Iranian accountant who help Iranian negotiators strike a landmark nuclear deal with world powers has reportedly been sentenced to five years in prison on charges of espionage. Iran’s semi-official Tasnim News Agency did not identify the defendant by name when announcing the news Wednesday, but Iranian lawmakers had previously identified him as Abdolrasoul Dorri Esfahani. He worked as an adviser to Iran’s central bank and is the only member of the Iranian team of negotiators known to be facing criminal charges, the Associated Press reported. His arrest would make him the latest in a handful of dual nationals to be arrested in Iran since the 2015 deal was reached. The United Nations has previously warned that the spate of arrests marks an “emerging pattern” since the nuclear agreement. Esfahani’s arrest was first reported in late August, and he was reportedly granted bail at one point before an appeals court upheld his conviction and sentenced him to five years.