PARIS -- Some 216,000 children -- mostly boys -- have been sexually abused by clergy in the French Catholic Church since 1950, a damning new inquiry has found.

The head of the inquiry said there were at least 2,900-3,200 abusers, and accused the Church of showing a "cruel indifference towards the victims", BBC reported.

A senior figure in the French Church expressed "shame and horror" over the findings, and asked for forgiveness.

One of those abused said it was time the Church reassessed its actions.

François Devaux, who is also the founder of the victims' association La Parole Libérée (Freed speech), said there had been a "betrayal of trust, betrayal of morale, betrayal of children".

The inquiry found that the number of children abused in France could rise to 330,000, when taking into account abuses committed by lay members of the church, such as teachers at Catholic schools.

For Devaux it marked a turning point in France's history: "You have finally given institutional recognition to victims of all the Church's responsibility - something that bishops and the Pope have not yet been prepared to do."

The report's release follows a number of abuse claims and prosecutions against Catholic Church officials worldwide.

The inquiry was commissioned by the French Catholic Church, and spent more than two-and-a-half years combing through court, police and Church records and speaking to victims and witnesses.

"These figures are more than worrying, they are damning and in no way can remain without a response," the head of the inquiry, Jean-Marc Sauvé, told reporters.

The report, which is nearly 2,500 pages long, said the "vast majority" of victims were boys, many of them aged between 10 and 13.

While the commission found evidence of as many as 3,200 abusers -- out of a total of 115,000 priests and other clerics -- it said this was probably an underestimation.

The Church not only failed to prevent abuse, but also failed to report it and at times knowingly put children in contact with predators, it said.

"The Catholic Church is, after the circle of family and friends, the environment that has the highest prevalence of sexual violence."

The BBC's Hugh Schofield says the revelations will be very hard to absorb, and will have people reeling in France.

Most cases assessed by the inquiry are thought to be too old to prosecute under French law.

But Sauvé called on the Church to pay reparations, as he denounced the "systemic character" of efforts to shield clergy members from sex abuse claim.

In response, the president of the Bishops' Conference of France (CEF), Archbishop Eric de Moulins-Beaufort, said: "My wish today is to ask forgiveness from each of you".

Earlier this year, Pope Francis changed the Roman Catholic Church's laws to explicitly criminalise sexual abuse, in the biggest overhaul of the criminal code for nearly 40 years.