The Iranian opposition in Belgium condemned the release of Iranian diplomat Assadollah Assadi, who was jailed in Brussels, asserting that it would continue its efforts to ensure he is put to trial in Belgium.
The Omani Foreign Ministry announced Friday that an agreement had been reached between Tehran and Brussels under which Assadi was released in exchange for a Belgian aid worker.
"The release of the terrorist... is a shameful ransom to terrorism and hostage-taking," the Iranian opposition said in a statement, adding it "encourages terrorism and betrays human rights by violating the ruling of the Constitutional Court."
It indicated that Assadi's release came even though the Constitutional Court stipulated in its ruling that the Belgian government must inform the victims' families before the convict is transferred so that they have a chance to return to court.
Tehran released a Belgian aid worker imprisoned in Iran as part of the exchange deal sponsored by Muscat, according to the two sides.
Assadi was convicted in Belgium in 2021 in connection with a foiled bomb plot in France targeting an opposition rally and sentenced to 20 years in prison. He was arrested in Germany in 2018 and transferred to Belgium.
Aid worker Olivier Vandecasteele was arrested on a visit to Iran in February 2022 and was sentenced last January to 40 years in prison and 74 lashes on various charges, including espionage.
Back then, the Belgian Justice Minister said Vandecasteele was accused based on false evidence, and his trial was in response to the sentence issued for Assadi.
On Friday, Belgian Prime Minister Alexander De Croo said that Vandecasteele was "currently on his way to Belgium," adding that if "all goes well, he will be with us tonight. Finally, free."
The Prime Minister said in a statement that Vandecasteele was taken to Oman on Thursday evening, where he was received by Belgian soldiers and diplomats, and underwent medical tests on Friday morning.
Iranian state television said Assadi had returned to Tehran, showing footage of him with officials, including spokesman Ali Bahadori Jahromi.
The spokesman tweeted on Friday that Assadi was innocent and is returning home after five years of illegal detention.
The Omani Foreign Ministry said earlier that an agreement had been reached to release both prisoners and transfer them to Muscat before returning to their respective countries.
"The Omani efforts have resulted in an agreement between the two sides for a mutual exchange deal."
"The Sultanate of Oman appreciated the high positive spirit that prevailed in the talks in Muscat between the Iranian and Belgian sides and their keenness to settle this humanitarian issue."
Oman's Sultan Haitham bin Tariq al-Said will visit Iran on Sunday for two days.