TEHRAN

An exiled Iranian opposition group on Friday accused Belgium of paying a "shameful ransom" after an Omani-mediated prisoner swap between Tehran and Brussels.

The Mujahideen e Khalq (MEK), an Iranian opposition group headquartered in Albania, released a statement decrying the release of an Iranian diplomat for a Belgian aid worker earlier in the day.

The announcement came a day before Sultan of Oman Haitham bin Tarik is slated to visit Tehran, which designates the MEK a "terrorist group," accusing it of carrying out attacks in the country and killing top political leaders and activists.

Iran's Foreign Minister Hossein Amir-Abdollahian took to Twitter to announce the release of diplomat Asadollah Assadi in exchange for Olivier Vandecasteele, who was imprisoned in Tehran in February last year.

Amir-Abdollahian said Assadi was "illegally detained" in Germany and France for more than two years "against international law" and was "now on way back to his homeland," referring to Iran.

He thanked Oman for its "positive efforts" in securing his release.

Iran's top human rights official Kazem Gharibabadi also issued a statement saying the Iranian diplomat would be home "in a few hours".

Last month, Iran's judiciary spokesman Masoud Setayeshi announced that Assadi, who had been sentenced to 20 years in jail in Belgium, was set to be released in a prisoner swap between Brussels and Tehran.

He said Belgium had requested a prisoner swap for Vandecasteele and that Tehran demanded the release of Assadi, a counselor at Iran's Embassy in Vienna.

Assadi, 48, was arrested in Germany in June 2018 days after a car allegedly carrying explosives was held in Brussels.

Belgian authorities at the time claimed the explosives were sent on the instructions of Assadi to target an MEK rally in France.

In February 2021, he was sentenced to 20 years in prison by a court in Antwerp, Belgian, the first time an Iranian diplomat faced such charges in a European country since the 1979 revolution.

Following the verdict, Iran's embassy in Brussels said the Belgian court lacked jurisdiction in the matter and vowed to pursue all legal mechanisms against it.

In January, Iran's judiciary sentenced Vandecasteele to 40 years in prison on four charges, including espionage and financial offenses.

The two sides took months to hammer out the swap deal. In March, Belgium's Constitutional Court upheld the agreement but legal challenges mounted by MKO delayed it.