"We wish, Holy Father, that you can be a guiding light in our night and that you take the time to get to know us," read the letter, sent by three members of the Parole Libérée, a group set up to help members of the Scout group who suffered sexual abuse in the 1980s.
The letter went on to explain that they were not "motivated by any spirit of vengeance" and simply want to "understand" why the priest was able to remain in office until August 2015.
"By retreating into silence, our cardinal has lost all credibility," Bertrand Virieux, a cardiologist and one of the three signatories, told Le Parisien, referring to Lyon Archbishop Philippe Barbarin, who failed to report the priest despite saying earlier this year that he had been made aware of the priest's behaviour “around 2007-8”.
Virieux explained: "That's why today we call on Pope Francis, in whom we trust."
A formal investigation was opened on January 27th after Bernard Preynat, the priest, admitted he sexually abused young Scouts over 25 years ago.
His lawyer, Federic Doyez, said Preynat told the judge that “the facts had been known by the church authorities since 1991”, when he was expelled from the independent Scouts group he had led for nearly 20 years.
Pope Francis has had a "zero tolerance" policy against sexual abuse in the church since his election three years ago. However some abuse victims insist the Vatican still has not gone far enough to protect children, even in the West, where intense media coverage of paedophile priests has led to greater scrutiny of church practices.
“Spotlight,” which chronicles The Boston Globe's investigation into sexual abuse in the Catholic Church and institutional efforts to cover up the crimes, won the Oscar for best picture last month.