Iran’s Foreign Ministry has announced that stem cell scientist Dr. Masoud Soleimani has been released after a year of imprisonment in the United States, according to Press TV.

Iranian Foreign Minister Mohammad Javad Zarif said in a tweet on Saturday that the top scholar, along with Xiyue Wang — a Chinese-born US citizen who had been sentenced to 10 years in prison for espionage in Iran in 2017 — had been delivered to the Swiss officials and would “be joining their families shortly.”

Soleimani arrived at Tehran Mehrabad airport on Saturday evening after he was released by the US in a prisoner swap. He was welcomed by his family members and Iranian officials upon his arrival.

Iranian Foreign Minister Mohammad Javad Zarif accompanied the released scientist from Zurich where the swap took place.

Soleimani, a 49-year-old Iranian scientist, left Iran on sabbatical last year but was arrested upon arrival in Chicago and transferred to prison in Atlanta, Georgia for unspecified reasons.