During the December raid of an apartment, Belgian investigators had found three handmade belts and explosives that could have been used in the deadly Paris attacks, federal prosecutors said in a statement on Friday.
The investigators also found a fingerprint on a bomb belt that belongs to Salah Abdeslam who is the brother of Brahim Abeslam, one of the known suicide bombers, in Paris. Salah fled Paris following the attacks and has not been found yet.
The apartment had been rented under a fake name, said the prosecutors and added that the evidence has proved that the Paris attacks were at least partially planned in Belgium.
Two of the attackers had lived in Brussels and police have arrested 10 suspects, one of whom was the renter of the apartment in the Brussels district of Schaerbeek.
The prosecutor's office told the BBC that it would be quite difficult to determine the date of the fingerprint as it was not dated.
They suppose that Belgian attackers, including Abdeslam - who went to the apartment, got the explosive belts, and then went to Paris, used the Schaerbeek flat.
Several suspects who have links to Abdeslam, have been arrested in Belgium.
Police are still searching for Abdeslam who is thought to have played a critical role in the incident.