The "Gallant Phoenix" project, created in 2016, is being headed by the United States and located at a US army base in Jordan, the daily said.

It seeks to collect and centralise traces left online by militants, remnants from jihadist actions anywhere in the world and even the personal belongings of Islamists seized after arrest, all to help prosecutions and provide evidence at trials.

The main contributors to the sharing effort are the Iraqi army, Kurdish forces, NATO allies and the members of the international military coalition against the Islamic State group.

Le Monde said military intelligence units are always eager to collect and evaluate objects left behind by enemy combatants, but "'Gallant Phoenix' gives this collection of evidence a framework and a system".

Some 700 documents relating to 500 jihadists have been handed over by Phoenix to ongoing investigations into acts of terror, the report said.