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A French member of the Islamic State terrorist group who is believed to be a key planner behind the deadly attacks in Paris last month is going on trial Tuesday on charges that he ran a network to recruit fighters to Syria.

Salim Benghalem, who has been featured repeatedly in ISIS propaganda and is believed to be in Raqqa, Syria, will be tried in absentia along with six suspects in Paris on allegations of running the network, which the government considers a major source of European fighters.

His wife, who left Syria with their children, has told investigators that he would return to France only to carry out an attack "with a maximum of damage." She has said he believed bombs were not enough, that "a series of killings is recommended." Benghalem, 35, has been linked to Cherif Kouachi, who along with his brother attacked the satirical newspaper Charlie Hebdo in January.

Multiple reported sources say Benghalem was actually the real planner of the Nov. 13 attacks in Paris, which left 130 dead. It is thought he was giving instructions to Abdelhamid Abaaoud, the person believed to be the "mastermind" behind the attacks. Intel sources reportedly say he would have been deeply involved in the planning, deployment of jihadis and coordination of the attacks.

"You won't see me again."  

— Salah Abdeslam, according to a witness

Benghalem is one of ten figures on the United States most-wanted global terrorist list.  He is also called "The Executioner," as it’s believed he has overseen the holding of Western hostages and has killed some. He has been the target of recent French airstrikes.

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A French official told The Associated Press Tuesday that a man believed to have helped secure a hideout for Abaaoud has been taken into custody.

The official, who requested anonymity to talk about the ongoing investigation, said Tuesday the 25-year-old man is believed to have been an intermediary with Jawad Bendaoud, who is the only person facing preliminary charges in France in the attacks.

Before his arrest, Bendaoud acknowledged in a live television interview providing housing for Abaaoud, but denied knowing they were linked to the Nov. 13 attacks. He described the transaction as "a favor." Abaaoud, his female cousin and an unidentified man died in a police raid at Bendaoud's apartment on Nov. 18.

The official did not provide details on the new arrest.

Belgium’s prosecutor said Tuesday that authorities there are still actively searching for a suspected eighth Paris attacker, Salah Abdeslam.

Abdeslam’s last reported sighting was at a train station in Brussels 16 days ago.

His last words, according to a witness, were "You won't see me again."

A report emerged Monday that investigators believe Abdeslam has escaped to Syria, but an official at the Paris prosecutor's office told Fox News that "...there are no elements at this stage to confirm such information."

Paris remained on high alert Tuesday during the second day of an international climate conference, although most of the 151 leaders there are expected to leave. So far the conference has gone ahead without incident.

French Prime Minister Manuel Valls said since the Nov. 13 attacks, there have been 2,000 police anti-terror raids, 210 people have been arrested and 320 weapons have been seized.

Fox News’ Greg Palkot and The Associated Press contributed to this report.