The suspect, Abid Tabaouni, was detained under a European arrest warrant from Austria after he had fled from Salzburg and was handed back to Austrian authorities last month.
The Belgian prosecutor's spokesman Thierry Werts, said that the handover was done quickly as “we confirmed that he did not have any ties to our country nor it appears to any of our cases.”
The Salzburg prosecutor's spokesman Robert Holzleitner also confirmed to AFP that Tabaouni has been held in Austria since August 25 and is suspected of belonging to a terrorist organisation.
Tabaouni is believed to have ties to the two alleged members of the Islamic State (IS) group, Algerian Adel Haddadi and Pakistani Mohamad Usman, who were arrested in Austria last December and handed over to French authorities in July as part of the investigation into the Paris attacks.
Investigators believe Haddadi and Usman, who face terror charges in France, travelled to the Greek island of Leros on October 3 on the same boat full of refugees as two men who took part in the November 13 attacks in France that left 130 people dead.
But Haddadi and Usman were detained by Greek authorities for 25 days because they had fake Syrian passports. Once released, they followed the main migrant trail and made it to Salzburg in western Austria at the end of November — after the Paris attacks.
Austrian police then arrested the two in December at a migrant centre a few hours after French authorities informed them the men could be in the country.
After his arrest, Haddadi told investigators that he had wanted to go to France to “carry out a mission,” according to a statement seen by AFP.
A source close to the investigation said that Haddadi “was meant to take part in the Paris killings with his travelling companions.”
US channel CNN reported, citing investigation documents, that Tabaouni was allegedly linked to the four men who had traveled as supposed refugees through Leros and that he also was probably meant to take part in an attack.