Survivors, families of victims and the local mayor have expressed deep misgivings about the production of a new film that will depict the days leading up to the Port Arthur massacre, which claimed 35 lives in 1996.

On Monday, streaming service Stan announced the film NITRAM, which has already commenced production in Geelong, Victoria. It is being helmed by Snowtown director Justin Kurzel, and stars Judy Davis, Anthony LaPaglia, Essie Davis and American actor Caleb Landry Jones as the gunman, whose first name is spelled backwards in the title.

But while little is known about the film at this stage, many have expressed their dismay at its potential to glamorise the killer, reignite conspiracy theories and retraumatise survivors of what, at the time, was the largest single shooter killing ever.

Hobart writer Justin Woolley was 12 years old when he witnessed the shootings from 100 metres away. On Twitter on Tuesday he said “the largest peace-time massacre by a single shooter in history” needed to be remembered and commemorated.

“But turning it into a piece of money-making entertainment? You’ll have to excuse me, and I would have though any right-minded person, for believing that is tasteless.”

Woolley said he wasn’t calling for the film to be censored. “I will be steering clear of it for obvious reasons, but I’m not advocating it be stopped,” he wrote. “They are free to make this movie, sure, but that also means I’m allowed to say I think it’s a horrible idea.”

Stan has undertaken to respond to the Guardian’s questions about whether any affected parties were consulted prior to the film going into production, and to concerns voiced by survivors and people in the Port Arthur community. Stan was unable to respond before publication of this story.

The film is being shot in regional Victoria instead of Tasmania, a decision that the Guardian understands was made out of respect for the residents in and near Port Arthur. The producers have also made it clear the film will not portray the actual massacre; only the events leading up to it and what may have been going on inside the head of the gunman.

But for Woolley this does not pass muster.

“As an author I know well that in order to create a story about this individual it is necessary to generate sympathy in the audience, at least have them relate to the subject. It is this, in a film portraying the life of Martin Bryant, that I strongly object to,” he wrote on Twitter.

“We do not need a study of the motivations of the perpetrator of this crime. We know them already.”

While little is known about the film at this stage, a spokesperson for the Alannah and Madeline Foundation, a children’s charity established by Walter Mikac after he lost his two young daughters and wife in the shooting, said the foundation was firmly against any film that could cause distress to those affected.

“The foundation is consistent in its views that out of respect for the survivors, it is not appropriate to give any platform to the perpetrator,” the spokesperson said, telling Guardian Australia that Mikac did not wish to discuss the project personally.

“Films like this do nothing to help the understanding of such grotesque, violent and inhumane acts,” she said.

“We don’t want to suppress creativity and art … we understand it’s a really difficult balancing act. But we’re not interested in giving the perpetrator a moment in the sun.”

The film was commissioned by the Melbourne international film festival, where it will premiere in 2021. On Tuesday, Screen Australia posted a tweet saying it had not funded NITRAM.

‘It’s a bit disappointing nobody thought to give us a heads up’

The Police Association of Tasmania, whose members were among the first on the scene of the 28 April 1996 shootings, also indicated their wariness over the potential impact of the film.

“A commercial movie about the Port Arthur mass murderer has the potential to severely affect the mental health of many, many Tasmanians, including current and past members of the Police Association of Tasmania,” the association’s president, Colin Riley, told the Guardian in a statement.

Kelly Spaulding, the mayor of Port Arthur municipality Tasman Council, said news of the film going into production could have already retraumatised some of those close to the tragedy.

“The community is pretty upset down here,” he said.

“Every time the media brings this up it brings back a lot of feelings which are obviously still quite raw, and it affects families not just down here but those living across Australia and overseas as well.”

Spaulding said Monday’s announcement “came like a bolt out of the blue”.

“It’s a bit disappointing nobody [the producers] thought to give us a heads up,” he said. “Obviously there’s nothing we can do to stop them ... I just hope people don’t mention [the gunman’s] name.”

The Alannah and Madeline Foundation said the producers had contacted them early on, but prior to Monday’s announcement they “weren’t aware of any logistical details or project development”.

The foundation is regularly contacted by researchers and creatives seeking to retell the story, they said, but “we politely decline as our focus is on the prevention of violence to children … we do not seek to glorify or publicise this crime”.

Apart from retraumatising survivors, the foundation’s main concern was the influence it might have on other deeply disturbed individuals.

“What we have seen in the past is that every time we put a spotlight on someone who has [committed a violent crime], the idea of instant celebrity attracts others,” the spokesperson said.

‘This is a tricky one’

The film has divided people on Twitter: while many have rejected its premise, others have highlighted how little we know about it.

“The discourse already is so perplexing,” tweeted film critic Glenn Dunks. “While I understand the desire to not put victims through the trauma of a reenactment film (is that what it will be? we don’t quite know), we have likely all watched stuff on 9/11 or Columbine. What makes Australian crime so off limits to artists?”

Composer John Haddock was among a group of six Opera Australia artists who sat next to the gunman at the Broad Arrow cafe that day. He later hid with many others in a stable at the far end of the complex, as the shots repeatedly rang out across the eerie landscape.

“My first reaction [to the film] was ‘this a tricky one’,” Haddock told the Guardian.

“Is this appropriate? It brings back terrible memories, even now as I talk about it. But this is fine with me because I read that the film won’t be reliving the massacre. If that was the case I could not bear it.”

Haddock said the trauma had lessened over the years, to the point that the events of that Sunday afternoon are now just a bad memory.

But he is concerned that fresh attention will stir up the conspiracy theorists and people like Pauline Hanson, who in March last year implied in comments recorded secretly by al-Jazeera that the 1996 massacre was a government conspiracy.

“It makes me angry, having lived through it,” he said.