The firefight on Tuesday, in which an Algerian national with suspected ties to Isis was killed, erupted after Belgian and French police searched a property in connection with the November 13th massacres in Paris, claimed by the militant organization.
Sky News reported on Friday that the man's name appeared on a list of 22,000 people with suspected terrorism connections, which was leaked to the TV station by a former Isis member earlier this month.
According to the list, the 35-year-old lived in Sweden for a period of time, where he is understood to have been married. It is believed he left Sweden in spring 2014 to travel onwards to Tel Abyad in northern Syria via Spain, Germany, France and Turkey.
Swedish media reported that the man, named as Mohamed Belkaid, is still listed in the Stockholm area. According to the Dagens Nyheter daily he spent time in jail and was fined on separate occasions in Sweden between 2009 and 2013 over minor offences, including using counterfeit documents and theft.
“It is common in these circles to have a multi-criminal background, everything from petty thieves to people who have committed more serious crimes,” terror expert Magnus Ranstorp told the TT newswire.
“It would be surprising if he had not been on Säpo's radar.”
Säpo, Sweden's security police, would not comment on whether or not the man was previously known to officers in the country, but told TT it had passed on “information” to Belgian police.
However a Swedish prosecutor said that the 35-year-old had never featured in a Swedish terrorism investigation.
"We constantly look at people who are relevant in France and Belgium and the names circulating. As soon as we have enough we start an investigation. But we have never had any investigations about this person or any persons close to him," said Hans Ihrman of the national prosecutorial unit which investigates cases relating to national security.
Another two suspects managed to escape when police raided the Brussels hideout on Tuesday. Sources close to the investigation told AFP that the officers visited the apartment believing it was rented under the same false identity as a hideout in the southern Belgian city of Charleroi used by the Paris attackers.
In the Charleroi hideout, police had found DNA traces of Paris attacks ringleader Abdelhamid Abaaoud as well as Chakib Akrouh, both of whom were killed north of the French capital days after the Paris attacks under a hail of police bullets.
According to Belgian daily De Standaard, police believe both properties were actually rented by convicted car thief Khalid El Bakraoui, 27, who is at large. His brother, Ibrahim El Bakraoui, is also known to authorities and served a nine-year sentence in 2010 after firing on police during a robbery, according to daily La Derniere Heure.
Sources close to the investigation told AFP the search on Tuesday was to verify if the El Bakraoui brothers were to be found at the apartment, though expectations were low as water and electric power had been cut off for weeks.