A Frenchman suspected of helping compatriot Islamist terrorist Medhi Nemmouche, held for killing four people at the Brussels Jewish Museum in May, has been formally charged, the federal prosecutors office said Thursday.
The French authorities extradited Nacer Bendrer to Belgium on Monday to face charges of "complicity in a terrorist attack," a spokesman told AFP.
Bendrer was picked up in December near the southern city of Marseille where Nemmouche was arrested after arriving by bus from Belgium following the attack.
Bendrer, 26, denied any connection with Nemmouche at the time.
Police said they found a Kalashnikov style assault rifle, two automatic pistols, a hunting rifle, and a magazine and ammunition when Bendrer was arrested.
Video surveillance footage of the attack on the Jewish Museum shows a man armed with a Kalashnikov.
Federal prosecutors confirmed late last month that the authorities were looking for a possible accomplice to Nemmouche.
Nemmouche, 29, had returned from Syria where he had been an Islamic State (ISIS) torturer and was charged in Belgium with "murder in a terrorist context."
The attack was the first of its kind in Brussels in three decades and shocked the country.
On January 15, Belgian police carried out a series of raids to foil what they said was an imminent Islamist plot to kill police officers. Two suspected terrorists were killed.