After outright denials on Wednesday, Belgium says it is examining Iran's request for a prisoner swap.

Alexander De Croo, Belgium's prime minister, said on Thursday that the government is currently evaluating Iran's request to swap jailed Iranian diplomat Asadollah Assadi for the detained Belgian aid worker Olivier Vandecasteele.

The Belgian Constitutional Court upheld a prisoner exchange treaty with Iran in March that could result in Assadi being swapped for Vandecasteele.

De Croo called for Vandecasteele's immediate release from Iran, one of an unknown number of diplomatic hostages held by the regime.

Only on Wednesday, the spokesperson for Belgian Justice minister Vincent Van Quickenborne denied a deal had been reached, calling it “a false message from a rogue state that specializes in making false statements".

Meanwhile, Daria Safaie, a member of the Belgian Parliament of Iranian origin said on Wednesday that to her specific question as to whether or not Belgium discussed the extradition of Assadolah Assadi, the foreign minister evaded the answer, suggesting there may be some hesitancy in Brussels as to the implications of moving forward with negotiations with a rogue state.

Former Iranian embassy attaché, Asadollah Asadi, 51, is currently serving a 20-year sentence in Belgium for alleged attempted murder and involvement in terrorism for his role in plotting a bomb attack near Paris in 2018 against the Mujahedin-e Khalq Organization (MEK), an opposition group in exile.

Security forces in Iran arrested aid worker Olivier Vandecasteele, 41, who has worked in a variety of humanitarian agencies since at least 2006. In January he was sentenced to 40 years behind bars and 74 lashes.