TEHRAN, Iran (AP) — An Iranian scientist imprisoned in the U.S. and acquitted in a federal trade secrets case returned to his homeland on Wednesday morning, a semiofficial Iranian news agency reported.

The report by the ISNA news agency included an image of Sirous Asgari, wearing a face mask and being welcomed by relatives.

A professor at Iran’s Sharif University of Technology, Asgari was indicted in April 2016, accused by U.S. federal prosecutors of trying to steal secret research from Case Western Reserve University. The Cleveland school had been working on a project for the U.S. Navy Office of Naval Research to create and produce anti-corrosive stainless steel.

Asgari was ultimately acquitted in November after U.S. District Judge James Gwin tossed out the case by the prosecutors.

Ken Cuccinelli, the acting deputy Homeland Security secretary, earlier told The Associated Press that the DHS had started to try to deport Asgari last December, following his acquittal. However, he said, Iran refused to recognize him as legitimately Iranian and provide him with a valid passport until late February.

His return was then postponed due to the coronavirus pandemic and restrictions on international flights. Additionally, Asgari contracted the virus but was later reported to have fully recovered.

Iranian officials had associated Asgari’s release with U.S. prisoners held in Iran potentially being freed, something Cuccinelli strongly disputed.

On Tuesday, Iranian Foreign Minister Mohammad Javad Zarif first said in an Instagram post that Asgari was on his way back to Iran. The ministry spokesman, Abbas Mousavi, rejected speculation of a prisoner swap.