The family of the Belgian aid worker being held in Iran has pleaded to their government to do “everything necessary” to secure his release.

In a video message released on Monday, Olivier Vandecasteele’s family said “Even though he’s innocent, he has been rotting away for nearly five months in total solitary confinement.”

“Today Olivier needs your support... It is unthinkable for our family that our democratic Belgium isn’t doing everything necessary to get innocent prisoners out of countries like Iran,” his sister Nathalie said in the video. 

She said her brother had received two consular visits that revealed he suffered major weight-loss and a foot infection, adding that “He has spent two months without even a mattress, in a cell lit up around the clock, and being subjected to daily psychological pressure from interrogators.”

Imploring authorities to get Olivier freed, his mother, who barely manages to fight back tears, said, “Since he finished his studies, he has been far from us to help others. Now, help us to get him out of there and bring him home so we can hug him close.”

Numerous people and groups from around the world have been warning about a prisoner exchange treaty between Belgium and Iran that was passed by the Belgian parliament’s foreign relations committee and will go to the full 150-member chamber July 14. 

A draft law could lead to the release of Assadollah Assadi, an Iranian diplomat serving a 20-year prison sentence in Belgium for planning a terror attack in Paris four years ago.