In 1941 the French novelist, playwright and film-maker Marcel Pagnol bought a chateau in a Provençal valley outside Marseille on the advice of his solicitor without even seeing it.

He proposed to transform the property into a “cinema city”, a French Hollywood set in the hills and lavender fields of southern France where he had holidayed as a child.

When he did finally visit the Chateau de la Buzine, named after a 17th-century aristocrat, it jogged a bittersweet memory, after the writer realised it was the same house whose caretaker and dog had terrified his mother and humiliated his family years earlier. The story would be central to the second of Pagnol’s autobiographic novels, Le Chateau de ma mère, more than a decade later.

Now the writer’s grandson, Nicolas Pagnol – the president of the association that has managed Chateau de la Buzine for the past five years – is at the centre of a dramatic row after the association was removed by Marseille city council.

The property, surrounded by seven hills, has a chequered history. It was requisitioned by the Nazis as a rest and recuperation home for troops during the second world war, by French soldiers after the liberation, then squatted in by Spanish refugees. Pagnol sold it shortly before his death in 1974 aged 79. By then it had lost its roof and was a ruin.

“The chateau had become as dilapidated as he had,” Nicolas Pagnol said. “In the end, he did nothing with the property, but he was reluctant to get rid of it because it was a memory of his mother.”

La Buzine was bought by property developers who built houses and a school on part of the estate, but did nothing to the chateau itself. No one in the Pagnol family gave the house a second thought.

But in 1995 the by then totally dilapidated property was acquired by Marseille city council, which spent a fortune renovating it and turning it into a cinema and cultural centre without mentioning the Pagnol connection. In 1997 it was declared a listed historic building.

In 2018, after tendering for an association to run the chateau, Nicolas Pagnol, who manages his grandfather’s literary and artistic estate, won the bid and became president of La Buzine – an unpaid position but one that gave him the opportunity to renew the family’s connection with the property.

“It was a huge success. In five years we increased the number of visitors eightfold and had a large programme of activities. We wanted it to be a place of popular culture open for all. We made it an attraction that would carry not just the name of Marcel Pagnol and Marseille but also Provence around the world,” he said.

However, when the five-year contract came up for renewal two months ago, Nicolas Pagnol was told he was being replaced by a workers’ cultural organisation.

“I was completely shocked, I almost fell off my chair. They had given the contract to an organisation that had never managed a cultural centre and whose proposition didn’t add up. Was it personal or political? I have no idea.

“Now they don’t seem to want the chateau to have anything to do with Pagnol, which is a shame. I’ve had thousands of messages from people all over France who are upset and angry so I set up a petition.

“Then the mayor called me and threatened to go through every single bill and invoice we’ve submitted for events at the chateau over the last five years. I said ‘go ahead; I’ve nothing to hide.’”

The Observer contacted Marseille city council for a response to what the French media described as a “Pagnolesque story” but there was no reply to repeated requests. In an earlier communique to French media, Jean-Marc Coppola, who is responsible for culture at the council, said the city was “fully attached to Marcel Pagnol’s heritage”.

“The city of Marseille has assured the Pagnol family that Marcel Pagnol’s heritage will be preserved and that his work will be given its rightful place on the site,” Coppola said.

After announcing the workers’ organisation bid had been dropped for unexplained reasons, mayor Benôit Payan told BFM TV he would run the chateau himself and would “probably go and read some of Marcel Pagnol’s work [there]”.

Nicolas Pagnol has been supported by opposition politicians and the actor Philippe Caubère, who played his great-grandfather in the film adaptations of Pagnol’s novels La gloire de mon père and Le château de ma mère.

He added: “Now I don’t think they know what to do. They’ve decided not to let the workers’ organisation run it but I won’t be doing it after they have tried to discredit my name and the family name.

“I cannot work with the city council now. They have tried to publicly damage my reputation and I have been subject to insults, threats and lies so it would be impossible, but I will return to the Buzine one day whatever happens. Marcel Pagnol is immortal, the mayor will change and he will be remembered for damaging the Pagnol name while claiming he is defending it.

“My only aim is to protect and promote my grandfather’s legacy. What would he have made of this? I think you’d have to read his play, Topaze, which is about the world of politics. He would be scandalised by the attitude of the mayor and his deputies.”

• This article was amended on 16 July 2023 to correct the spelling of Marcel Pagnol’s play Topaze.