Belgian aid worker Olivier Vandecasteele has been sentenced to 28 years in prison in Iran for a “fabricated series of crimes,” Belgium’s justice minister said on Wednesday, adding the government was doing everything possible to secure his release.

Vandecasteele had been sentenced as retribution for a jail sentence Belgium imposed on an Iranian diplomat last year, Justice Minister Vincent Van Quickenborne said in the Belgian parliament.

“This is a compatriot who was innocently arrested in February and has been held under inhumane conditions since,” he said.

Belgium has repeatedly said there are no grounds for the detention of Vandecasteele, 41.

The Iranian Foreign Ministry declined to comment.

“It’s a disgrace and a tragedy for Olivier and his family,” family spokesman Olivier Van Steirtegem told Belgian newspaper Het Nieuwsblad. “He is innocent and the victim of a larger, shady international game.”

Swap suspended

Last week, the Belgian constitutional court suspended an agreement between Iran and Belgium that would have made it possible to swap prisoners between the two countries. But Van Quickenborne said the agreement would legally still be relevant for Vandencasteele.

That deal was seen by his family as his only hope. Belgian media suggested he might be swapped for Assadollah Assadi, an Iranian who last year was found guilty of attempted terrorism and sentenced to 20 years’ imprisonment in Belgium in connection with a foiled plot to bomb a 2018 rally of the National Council of Resistance of Iran (NCRI), a French-based dissident group.

Van Quickenborne said Vandecasteele’s situation was directly linked to the sentencing of Assadi, who worked as a diplomat at the Iranian Embassy in Vienna, Austria.

Prosecutors said his position was a cover for actions against members of the Iranian opposition in Europe.

Iran dismissed all terrorism charges and called the Paris attack allegations a “false flag” stunt by the NCRI, which it considers a terrorist group.