For most film directors, the nail-biting action unfolds on screen. Not, however, for François Ozon. The theatrics over his latest film played out in the French courts as he fought a last-minute attempt to stop it being released and found himself at the centre of a legal and national controversy. Today, Ozon can almost but not quite laugh about his starring role in the off-screen drama that earlier this year came perilously close to having his €5.9m (£5.2m) film By the Grace of God – the story of a real-life scandal involving a paedophile priest – canned.

“I suppose I was naive to think there wouldn’t be attempts to stop it coming out,” he says. “There was huge tension over the court case and we really didn’t know if the film could be released. The judgment was on the Tuesday; the film was due out on the Wednesday. We only knew the decision the night before.

“There were two court cases, but each time there has been legal action the judges have found in our favour. Fortunately.”

Even for Ozon, who is known for zigzagging across cinematic genres – farce, horror, comedy, psychosexual – By the Grace of God is a departure from style, a dramatised retelling of the story of the victims of Bernard Preynat, a former Catholic priest in the city of Lyon who is believed to have abused 70 children over three decades.

Without morphing into documentary, the film presents the facts of the most serious scandal to hit the Catholic church in France. Preynat’s penchant for young boys was widely known and covered up by his superiors, who were more concerned to put the reputation of the church before the shattered childhoods, fractured families and splintered lives of the survivors. Shockingly, even after Preynat admitted in apologetic letters to parents that he was “sick” and had “a problem with children”, his diocese protected him and he continued working with youngsters.

Preynat has since been defrocked but is awaiting trial in the criminal courts. The legal row erupted over whether the film contravened his right to the presumption of innocence. The courts concluded it might, but still found in Ozon’s favour. “The judges weighed up two principles of French law: the freedom of artistic creation and the presumption of innocence. They decided that for this film, the freedom of creation was more important and it was in the public interest that the film come out,” Ozon says.

The figures testify to the public’s interest: since its release in France in February, By the Grace of God has been seen by a million people and has so far taken more than $7.2m (£5.8m) at the box office worldwide. It won the Jury Grand Prix prize at the 69th Berlin international film festival and has been likened to Spotlight, the Oscar-winning American film about a team of journalists uncovering paedophilia in the US Catholic church.

Sitting on a plush green velvet sofa in his film company’s offices in a discreet building in the financial district a stone’s throw from the Paris stock exchange, Ozon cuts a suave figure in neat blue jeans, a navy polo shirt and brown suede boots. He has the face of a screen matinee idol but after stage lessons when young decided he was a “terrible” actor and preferred the other side of the camera.

Those who label him the enfant terrible of French cinema for a directing style that subverts typical genres see him as provocative; fans view his eclectic output as thought-provoking. Filmmaker magazine compared him to Alfred Hitchcock and Rainer Werner Fassbinder and labelled him the “hardest working director in France”. Some identify the influence of Ken Loach in Ozon’s often stark film-making.

In France, he is better known for lighter films: thrillers, comedies, musicals and melodramas, mostly starring women, including 8 femmes (8 Women) with Catherine Deneuve, Isabelle Huppert, Fanny Ardant and Emmanuelle Béart and Sous le sable (Under the Sand) with Charlotte Rampling.

By the Grace of God came about while he was looking to make a new film about three or four middle-aged men showing their emotions and “masculine fragility” and stumbled across La Parole Libérée (The Liberating Word), the website of an association of Preynat’s victims on which they gave their testimonies.

The film begins in 2014, when 40-year-old Alexandre, a successful banker and father of five, from Lyon, who attends mass and sends his children to Catholic schools, is horrified to discover that Preynat, who abused him as a boy at scout camp, is still working with children.

Alexandre writes to the diocese and the priest’s superior Cardinal Philippe Barbarin asking them to stop this, but is frustrated and increasingly angry that the church is determined to sweep the matter under the carpet. “When I met Alexandre, he came with a big file with all the mails he had sent and the responses and said, ‘Do what you want with them?’ I began reading and found it incredible. At first, I thought it would be great material for a play, then afterwards perhaps a documentary. Then I realised the victims had already told their stories to the press and if they trusted me it was because I was a film director and they wanted a Spotlight à la Française.”

Cardinal Philippe Barbarin, who in March was convicted of failing to report the abuse of children, pictured with Pope Francis earlier this year. Photograph: EPA

The film also focuses on two other victims, now adults but struggling to deal with long-buried memories of Preynat’s abuse and the devastating effect it has had on their lives and families.

Ozon says he felt an immense sense of responsibility to be scrupulously true to the victims’ stories. The words of Preynat, Barbarin and a third person, the diocese’s volunteer psychologist Régine Maire, are taken verbatim from what they told the press and legal statements, he says. The film title comes from Cardinal Barbarin’s response when asked why he had not acted earlier to remove Preynat from contact with children. “By the grace of God most of these cases are now out of date,” he replied, meaning that they were covered by the statute of limitations and no legal action could begin.

Maire was accused of covering up Preynat’s abuse but was acquitted after a judge decided she had acted in “good faith”. She went to court to prevent her real name being used in the film, but the action failed. An appeal by Preynat against the court’s decision to allow the film to be released was dismissed in June, allowing it to be streamed and released on DVD and abroad.

On screen, Barbarin is ambiguous. His sympathy for the priest’s victims is portrayed as being overridden by a greater desire to avoid scandal and protect the church. In March, after the film’s release, Barbarin was convicted of failing to report the abuse and taking months to follow a Vatican directive to remove Preynat from duties that put him in contact with children. He has appealed against his conviction.

“The weight of this responsibility to tell these men’s stories was on my shoulders. I w anted to show them as they are, their humanity, their complex characters, but also like we see in American films, the ordinary heroes taking on a powerful institution,” Ozon says. “I wanted the film to show them as heroes because they really are and they changed things. Barbarin was convicted, Preynat defrocked, so they succeeded.”

In a powerful and painfully tense scene, the diocese organises a meeting between Alexandre and Preynat. Known as a “confrontation”, this is a legal process where the victim meets their attacker, usually before a judge. We see Preynat admit he remembers Alexandre and confess: “I have always been attracted to children… it is a blot on my life and it has always caused me pain. It’s a sickness.”

The paedophile priest then contests Alexandre’s calling him a “paedophile”, arguing that the strict meaning of the word is “someone who loves children… and we are all supposed to love children”. As the French magazine Le Point wrote: “Preynat is considered a monster… even by himself.”

Afterwards, Maire, who acts as a mediator, is shocked by Preynat’s failure to demand forgiveness, but advises Alexandre not to “scratch the wounds too much”. Even Alexandre’s parents question why he is “digging up all these old affairs”.

A scene from By the Grace of God. Photograph: Alamy Stock Photo

“I asked Alexandre if he had really wanted Preynat to ask for forgiveness and he said he honestly didn’t know. He was happy with how the meeting went because he wanted Preynat to admit he had abused him, because we know lots of priests have denied it,” Ozon says. “What he wanted was for someone of authority in the church, in this case Barbarin, to hear Preynat admit he was a paedophile and to do something about it.”

It was while hearing Preynat’s victims recount how he abused them as boys while they attended catechism or scout camps that Ozon was struck by a revelation of his own.

“I was listening to the stories of what had happened to these men as children when I remembered something. I must have been seven or eight and went to catechism and we were playing hide and seek,” Ozon says. “The priest, he was a short man, pushed me into the corner behind a door against the wall and said it was a good hiding place. He held me and I remember he was breathing heavily. At the time, I just thought he was bizarre – and he smelled bad too – then someone shouted ‘game over’ and I ran off. But it was one of those shocking, vertiginous moments when I suddenly realised that if I hadn’t run off, if that priest had touched me, then my life would also have been turned upside down.”

In its review of By the Grace of God, the British Film Institute described it as a “welcome act of solidarity with a group of men who have been betrayed and ignored by the very institution sworn to protect the helpless”.

Tension is maintained by Ozon’s use of subtle often soft-focus flashbacks to the boys’ ordeals and the race to find a victim whose abuse is more recent and can be used to bring Preynat to trial.

“When I researched this subject, what really shocked me was that everyone knew [about Preynat] and nobody did anything,” Ozon says.

“For 30 years, Preynat was a priest in the region and he looked after hundreds of children. Of them, 70 have come forward but he had contact with around 300 children a year for 30 years… some are now dead, some killed themselves and others don’t want to speak out. For some, the facts are covered by the statute of limitations so they feel there’s no point speaking.

I realised I had run away as a child without any understanding that the priest had a sexual desire François Ozon

“Preynat was honest and that was part of the drama. He never denied it. He said he had a problem with kids; he sent letters to the parents in the 1990s in which he admitted it. Barbarin knew about it. Still nothing happened.”

Ozon’s own epiphany when talking to Preynat’s victims has given him a profound empathy that comes through in the film and when he talks. “I realised I had run away as a child without any understanding that the priest had a sexual desire. It’s only suddenly, today, I realise that. At the time, I just thought, ‘Why is he breathing like that? It’s bizarre.’

“So I asked the victims why they didn’t run and each one told me they felt paralysed. I wanted to show this in the film, how each time the child is like a lamb who goes to the wolf because they trust the adult and they don’t know there is danger.

“A child has no weapon against this. Psychologists say when this happens to a child their brain switches off and they don’t understand what’s happened. It’s only when they become an adult it comes back and they realise what has happened. That is the horror. I think what all this shows is that a molested child is a ticking time bomb waiting to go off. And when it does, it touches the whole family.”

When filming started, Ozon says he worked in secret with a false working title and outside France to avoid alerting anyone to the real subject. He says he did not meet Barbarin, Preynat and Maire and has no wish to.

The film recounts events entirely from the point of the victims and the others are secondary characters whose words we’d already heard from their statements and depositions. What I showed are the victims in their private lives with their families, friends, parents – all the things people had not spoken about. This is what interested me, to show how this abuse destroyed the victim’s whole family. How it woke up so many things, the guilt felt by the parents, the jealousy of siblings, the anger, the hatred.”

When the film was ready, Ozon organised screenings around the country, inviting clergy to attend. “We went to towns to show the film and invited priests, cardinals, nuns – anyone from the diocese who wanted to come. At the beginning, I think the church was afraid of the film, then they realised it was quite objective and showed the facts,” he says.

“What helped was that Alexandre is very Catholic and they realised it was not a film against Catholicism but against the functioning of the church as an institution. The problem was the institution.

Ozon insists his film is not an attack on Catholics but on the “church as an institution”. As the eldest of four children growing up in a practising Catholic family in Paris, he attended catechism and mass and says he is pleased to have had a Catholic education. Openly gay, he says he lost his faith as an adolescent because of what he saw as the church’s “hypocrisy towards issues like sexuality”.

Having succeeded in getting By the Grace of God released, he says it is for the audiences to run with the cause in support of victims and for the church to adopt a more transparent and reactive approach to stop abuse by priests.

At the end of the film, one of Alexandre’s children asks him if he still believes in God.

“The question should have been, ‘Do you believe in the church?’ Faith and the institution are not the same thing,” Ozon says.

He has been accused of “manipulating” emotions in the film, but the response in France, even from Catholics, has been largely positive, Ozon says. Vincent Neymon, spokesman for the Bishops’ Conference of France, told France 2 television it was “another stone in the building that is the fight against paedophilia”. Le Monde declared Ozon had succeeded in making a film that was both a “sensitive telling of a collective drama and a political film”.

“It’s not a political film but of course there is a political aspect. I knew the film would make people talk about these things but not as much as it has,” Ozon says. “If the film gives people the courage to speak out about what has happened, that is wonderful. The victims were absolutely stunned when they saw it… it shook them up. It’s complicated when you see your own stories told. But they liked it and thanks to the film their association received more money and other victims came forward so it’s a kind of recognition for them.”

He adds: “People often ask: ‘Do you think cinema can change the world?’ and everyone always replies, ‘No’. But here, you know I like to think maybe we did change things a little bit. And this was a surprise. I didn’t imagine it would have the positive effect that it’s had.”

• By the Grace of God is released in UK cinemas and on Curzon Home Cinema on 25 October



