From the United Nations:

Mohammad Baquer Namazi (born 3 December 1936 (85 years old)) is an Iranian-American former civil servant who served as Governor of Khuzestan Province under Shah Mohammad Reza Pahlavi. He is currently imprisoned serving a 10 year sentence for colluding with the U.S.

On October 13, 2015, Iran’s Islamic Revolutionary Guard Corps arrested his son, Siamak Namazi, while he was in the country on business. The Revolutionary Guards subsequently arrested Baquer as well on February 22, 2016, when he flew into the country to visit his imprisoned son. On October 17, 2016, Iranian authorities sentenced Baquer and Siamak to ten years in prison for “collusion with an enemy state,” in reference to the United States. (Wiki)

He has been released to pursue medical care abroad for one week from Iran’s Evin Prison. It is not currently clear where he will get treatment.