Police found a body after they stormed an apartment on Tuesday.
Earlier in the afternoon, an anti-terror raid turned violent when at least one suspect shot at police through a door.
Four officers were injured, one seriously.
It is not known if the man found dead was one of the people police were looking for in the raid in the Forest neighbourhood.
Forest mayor Marc-Jean Ghyssels told local media two people had barricaded themselves in a home.
A prosecutor, who asked not to be identified, said it was unclear whether suspects from the raid were on the run. He said many people fled the area when they heard gunfire.
The anti-terror raid was linked to the gun and bomb attacks on a stadium, cafes and a concert hall in Paris but police did not expect violent resistance yesterday, the prosecutor said. That indicated they were not targeting a major suspect such as Salah Abdeslam, who fled Paris and remains on the run. Most of the attackers died that night, including Abdeslam’s brother Brahim, who blew himself up.
Four months on, Belgian police and magistrates are still piecing together the role Belgian nationals and others living in Belgium played in aiding the Paris attackers.
The suspected ringleader of the attacks was a Brussels resident, Abdelhamid Abaaoud. Another attacker, Bilal Hadfi, was said to have lived for a time in the Forest neighbourhood. Hadfi blew himself up outside the Stade de France stadium in Paris the night of the attacks and Abaaoud was killed in a police raid in a Paris suburb soon after.
Yesterday, the Forest neighbourhood was locked down for five hours after the initial burst of gunfire. Police sealed off a wide perimeter around the area where the shots were heard to keep the many bystanders at a safe distance. A helicopter was hovering overhead on patrol. The operation took place in a multicultural neighbourhood, which has a big Audi car factory nearby. Audi asked its personnel to stay at the plant while the police raid was going on.
Belgian authorities have stepped up their counterterror efforts since a lone gunman killed four people at the Brussels Jewish museum in May 2014.