DUBAI, United Arab Emirates -- Belgium and Iran exchanged prisoners on Friday in a controversial move that saw an Iranian diplomat convicted of attempting to bomb exiles in France returning to Tehran bedecked in flowers while a visibly gaunt aid worker headed back to Brussels.

Belgian Prime Minister Alexander De Croo said in a statement that the aid worker, Olivier Vandecasteele, had been freed and said that for him, “the choice was always clear: Olivier's life was always the most important."

He said Vandecasteele had been unjustly held in Iran for 455 days and added that “in Belgium, we abandon no one. Not least someone who is innocent,” whatever the legal and diplomatic consequences.

Iranian state television later showed the diplomat, Assadollah Assadi, being welcomed at the airport by Iran's judiciary chief and the secretary of human rights council Kazem Gharibabadi. Assadi had a floral wreath placed around his neck and held a bouquet of flowers — a hero's welcome in Iran.

Despite the contentious optics, Belgian Justice Minister Vincent Van Quickenborne said he would do it again, anytime.

“There is a moral compass. If you have the choice between freeing someone innocent or keeping one, or 10 guilty in prison, then you always have to choose the fate of the innocent,” he told VRT network.

He compared the exchange to last December's U.S.-Russian prisoner swap between WNBA basketball star Brittney Griner and Russian arms dealer Viktor Bout following her trial and conviction on drug possession charges in Moscow.

“The United States did it too," Van Quickenborne said, adding that it is his "absolute duty to help every innocent Belgian.”

The swap took place in Oman, long an interlocutor for the West with Iran. Its foreign ministry said and added that "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.” Muscat is Oman's capital.

In January, Iran sentenced Vandecasteele to a lengthy prison term and 74 lashes after convicting him of espionage in a closed-door trial. He was also fined $1 million. Vandecasteele was arrested in Iran in February 2022 while packing up his belongings, after working with the Norwegian Refugee Council and Relief International in the Islamic Republic from 2015 to 2021, according to Amnesty International.

His family and the Belgian government strongly denied Iran's claims, made without offering evidence, that he was a spy.

In 2021, Belgium convicted Assadi of masterminding a thwarted bomb attack against an exiled Iranian opposition group in France and sentenced him to 20 years in prison. Prosecutors tied Assadi to a couple, stopped by the Belgian police and found with 550 grams (1.21 pounds) of TATP explosives and a detonator in 2018. They had been trying to target a meeting in Villepinte, France, of the Mujahedeen-e-Khalq, an exiled Iranian opposition group known as the MEK.

Among dozens of prominent guests at the rally in Villepinte that day were then-President Donald Trump’s lawyer, Rudy Giuliani; Newt Gingrich, former conservative speaker of the U.S. House of Representatives; and former Colombian presidential candidate Ingrid Betancourt.

Assadi was arrested a day later in Germany and transferred to Belgium. Belgian intelligence identified him as an officer of Iran’s intelligence and security ministry who operated undercover at the Iranian Embassy in Austria. Iran denied Assadi's involvement.

Iran has carried out abductions and other plots against dissidents abroad in the past. However, Iranian Foreign Minister Hossein Amirabdollahian referred to Assadi as “an innocent diplomat” in a tweet after his release on Friday. Iranian state television called the case against him “bogus accusations.”

In a statement, the MEK condemned Assadi's release, calling it “a shameful ransom to terrorism and hostage-taking.”

“This will embolden the religious fascism ruling Iran to continue its crimes in Iran through repression and regional and international terrorism,” the group said.

Iran has detained a number of foreigners and dual nationals over the years, accusing them of espionage or other state security offenses and sentencing them following secretive trials in which rights groups say they have been denied due process.

Critics have repeatedly accused Iran of using such prisoners as bargaining chips with the West.

Iran, facing Western sanctions over its rapidly advancing nuclear program, has faced protests in recent months and economic strain. Oman's Sultan Haitham bin Tariq was already scheduled to visit Tehran this weekend before the announced prisoner swap.

___

Casert reported from Brussels. Associated Press writer Samuel Petrequin in Brussels contributed to this report.

___

Follow Jon Gambrell on Twitter at www.twitter.com/jongambrellAP.

magnifier linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram