Rachid Kassim is believed to have introduced the two attackers, Adel Kermiche and Abdel Malik Petitjean, both 19, to one another before they slit the throat of 85 year old Fr Jacque Hamel at his church in Saint-Etienne-du-Rouvray.
Abdennour Bentoumi, leader of the mosque in the 29 year old's hometown of Roanne, told France Television: "He tried to lure young people. He told them, heaven isn't praying. There's another way."
Kassim, who is now thought to be in either Syria or Iraq, has been linked to at least four attack plots in France since June, according to three people with knowledge of the investigation by authorities.
Using encrypted internet forums to direct recruits on how to undertake attacks on European soil, he is, most recently, suspected of being in contact with an 19 year old woman within a cell of French women behind a failed car bomb plot.
Kassim appeared in an video where Islamic State claimed responsibility for a truck attack in Nice which left 86 people dead (memorial pictured above) and he was also seen beheading a captive in Iraq.
He is believed to have drawn up a hit list of public figures which was left behind by killer Larossi Abballa who stabbed two police officials at their home in Magnanville, Paris on June 14.