Dozens of Belgian police, including armed special commandos, surrounded houses in a residential street in the Brussels district of Molenbeek on Monday 16 November.
State-controlled media RTBF carried a denial of a report by private broadcaster RTL that Salah Abdeslam, a Frenchman based in the Belgian capital, had been detained. Abdeslam is believed to escaped across the Franco-Belgium border after being involved in the terror attacks in Paris.
Police have put out a wanted poster for the 26-year-old. Salah is thought to have rented the black Volkswagen Polo used by the group that attacked the Bataclan concert hall and found laden with Kalashnikovs rifles in the aftermath, Associated Press reported.
He was born and bred in Belgium, although police have described him as a French national. In the hours after the attacks, French police stopped Abdeslam and two other men close to the border with Belgium, but allowed them to go on their way because their names were not at that stage on any wanted list.
Ibrahim Abdeslam, the brother of on-the-run attacker Salah, was identified by prosecutors as the man who rented a Seat vehicle used in the attacks. He carried out the suicide attack at the Comptoir Voltaire cafe. Ibrahim, 31, was a French national based in Belgium.
A third Abdeslam brother, who has not been named, is believed to have been among seven people arrested on Saturday in the Molenbeek-Saint-Jean district of Brussels, suspected of being connected to the attacks.
Brussels police said the operation was related to the Paris attacks.
The poor district of Molenbeek, home to many Muslim immigrants, has been at the centre of investigations of militant attacks in Paris over the weekend, after it emerged that two of the attackers had lived in the area.