TEHRAN- The release of an Iranian diplomat from a Belgian jail has been described as a major victory for Iran and a major setback and embarrassment for the anti-Iran Mujahedin-e Khalq (MKO) terrorist group by Iran’s vice president for legal affairs.

The arrest and trial of diplomat Assadollah Assadi, according to Mohammad Dehghan on Saturday, was a flagrant violation of the fundamental rule of diplomatic immunity, and his release demonstrated the Islamic Republic’s commitment to defending the rights of Iranian nationals everywhere in the world.

He congratulated the country’s diplomatic apparatus and the Assadi family on his release.

The foreign ministry of Oman announced on Friday that Muscat successfully mediated between Iran and Belgium in clinching a deal on swapping prisoners.

“In compliance with the directives of His Majesty Sultan Haitham bin Tarik, to fulfill the requests of the Iranian and Belgian governments to assist in resolving the issue of detained citizens in both countries, the Omani efforts have resulted in an agreement between the two sides for a mutual exchange deal,” the ministry said in a statement.

The statement added, “The individuals who were released have been transported from Tehran and Brussels to Muscat today, Friday, May 26, 2023, in preparation for their return to their respective countries.”

It concluded, “The Sultanate of Oman appreciates the positive high-level spirit that prevailed during the discussions in Muscat between the Iranian and Belgian sides, and their commitment to resolving this humanitarian issue.”

Assadi arrived in Tehran on Friday afternoon. He was welcomed by Iran’s human rights chief Kazem Gharibabadi and government spokesman Ali Bahadori Jahromi.

Iranian Foreign Minister Hossein Amir Abdollahian was upbeat over the release of the diplomat. In a tweet, he said, “Mr. Assadollah Assadi, the innocent diplomat of our country, who was illegally detained in Germany and Belgium for five years in violation of international law.”

Amir Abdollahian also said, “I thank the Sultanate of Oman for its positive efforts in this direction.”

Belgium released Assadi who had been in prison since 2018. Assadi was detained in Belgium in 2018 over charges of trying to target an Iranian opposition group. He had been sentenced to 20 years in prison.

In June 2018, Belgian officials said that two persons in Belgium received homemade bombs from an Iranian diplomat after Belgium's police had stopped a vehicle carrying the contraband. He was charged of preparing an assault against the MKO, which the Iranian government vehemently denies.

In March 2023, a plea for the revocation of a treaty with Iran that permits the exchange of prisoners between Iran and Belgium was rejected by the Constitutional Court of Belgium. The court said that it had rejected the annulment request made by the MKO.