According prosecutors in the French city of Lille, 46 people were taken into custody as part of a wave of arrests of suspected arms dealers.
"This vast operation involves 71 clients in this sector, mobilised 24 research sections of the national police as well as many members of the national police," the prosecutor of Lille said in a statement sent to AFP.
The first judicial probe started on March 31, 2014 after the Interregional Specialised Court (JIRS) of Lille called to to investigate the facts of the acquisition, possession, trade and importation of weapons by organised gangs.
If a criminal conspiracy for preparation of crimes or offences is proven, the suspects may be punished with up to ten years imprisonment.
The first arrest was in February 2015 after an unidentified suspect was found to be hiding many guns including machine pistols in his houses in France and Luxembourg.
According to an unnamed source, the weapons were sold on the internet by a French national to other countries.