Oman says an Iranian scientist held by the U.S. since late 2011 has arrived in Oman.
Friday's report on Oman state TV gave no further details. Oman has served as a mediator between Washington and Tehran before.
The scientist, Mojtaba Atarodi, was in U.S. custody since December 2011 over allegations he bought advanced technological equipment in violation of U.S. sanctions on Iran.
Iran's official IRNA news agency said this week that the U.S. released Atarodi, a microchip expert at Tehran's Sharif University.
In September 2011, two Americans convicted of espionage by Iran were freed and traveled to Oman, which also briefly hosted a third member of the group after her release a year earlier. The three Americans said they were hiking in northern Iraq and strayed across the Iranian border.