One of the suicide bombers in the Paris attacks reportedly had links to a Belgian Islamic State militant believed to be the mastermind of a jihadist cell dismantled in January.
The name of Paris attacker Brahim Abdeslam appears in several police files alongside leading militant Abdelhamid Abaaoud relating to criminal cases in 2010 and 2011, Flemish-language newspaper De Standaard reported on Monday.
"Investigators see a link with Verviers," it said, referring to an eastern Belgian town where police shot dead two militants in January and broke up a cell aiming to kill Belgian police officers in the streets days after the Charlie Hebdo attacks in Paris.
Belgian prosecutors were not immediately available for comment.
Abaaoud - a 27-year-old Belgian of Moroccan descent who allegedly led the group and had fought with the Islamic State group in Syria - remains at large.
He has claimed in the IS English-language magazine Dabiq to have rejoined the group in Syria.
Both Abdeslam, a Belgium-based Frenchman who blew himself up outside a bar on Boulevard Voltaire, and Abaaoud lived in the Brussels district of Molenbeek, which has a reputation as a hotbed of Islamic militancy.
French police have launched an international manhunt for Abdeslam's Brussels-born brother Salah, who is also said to be linked to the Paris attacks.