Victims of a French priest who has admitted sexually abusing boys have written to the Vatican to ask for an audience with Pope Francis about an alleged cover-up by the archbishop of Lyon.

Priest Bernard Preynat was charged in January after victims came forward with claims he had sexually abused Scouts between 1986 and 1991. Prosecutors say he has admitted the charges.

The victims have filed complaints against several senior officials in the Lyon diocese in eastern France, including Cardinal Philippe Barbarin, accusing them of being aware of the abuse but failing to report the priest.

"We no longer have any confidence in our diocese which is judge and jury in this case," Bertrand Virieux, a member of the victims' association, told AFP.

"We therefore appeal to the pope and we would like him to take firm action," he said.

Mr Virieux said the group did not feel it was their job to call for Barbarin's resignation. "It is up to the pope to judge," he said.

Barbarin, who has been archbishop of Lyon since 2002, has argued that he did not have ultimate responsibility at the time and that it was not until 2007 that he first heard rumours of the abuse.

The diocese said it only received the first statement from a victim in 2014. On the advice of the Vatican, it removed all forms of ministry from Preynat in May 2015.

The Vatican has given the cardinal its backing, saying he had shown "a great deal of responsibility" in dealing with the matter. But the victims say in their letter to the pope that they simply cannot understand the vote of confidence from the Vatican.

"We are trying to understand how a man managed to commit abominable acts against children without the hierarchy finding it necessary to put him in a position where he could cause no further harm or go to the police," the victims say.