Waleed Aly has slammed the writer-producer of a film about Port Arthur massacre killer Martin Bryant for perpetuating false and potentially upsetting conspiracy theories.

On Monday night’s episode of The Project, Aly questioned filmmaker Paul Moder’s motives in making a film about Bryant ahead of the 20th anniversary of the Tasmanian massacre.

The proposed movie has been hit with backlash from victims’ families, with Moder claiming he plans to cast an “internationally renowned” actor to play Bryant, responsible for murdering 35 people and wounding 23 others.

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Moder admitted he had struggled to write the script without the support of the survivors and victims’ families.

“It’s very, very difficult. I’ve written a few scripts in my time but I have to say writing this script was the most toruturous thing I’ve ever done,” Moder told The Project panel.

“Principally because there is so much misinformation, so much controversy, conspiracy, and spurious agenda that it is very hard to separate the wheat from the chaff.”

Aly interrupted Moder to take issue with his suggestion that Bryant was the “alleged” killer, despite confessing and being convicted and imprisoned for the crime.

“There are things like, because there was no open trial, there were never any fingerprints taken from the scene that proves that Martin was there, there was never any ballistic evidence matching the firearms to the crime scene or Bryant to the firearms,” Moder explained.

“There’s not going to be any ballistics evidence because there was a confession,” Aly hit back.

“Of course it hasn’t been presented publicly, that’s the way the system works.

“If there was a defensible case, in this case, it would have run to trial.

“But the fact that someone can just say – in a case where there was a conviction, and really do debate about who did this – ‘oh look there was a discrepancy over here’, that’s the stuff of conspiracy theory, that’s how you build a conspiracy theory.

“You try to inject doubt where there just isn’t any.”

“A lot of people out there don’t agree with you, who just think, look, there’s not enough evidence,” Moder said.

“You are in absolutely no position to say that, Paul,” Aly responded.

“This is absolutely unremarkable as a legal proceeding from what I can tell and when you say ‘oh there’s all this stuff out there that might make it remarkable’, that’s what leads me to believe there’s something really weird going on here.

“And I can completely understand why survivors and their families would say ‘no, we don’t want this made'”.

“It feels like a particularly distasteful time to be having this conversation,” Aly’s co-host Carrie Bickmore added, referring to the upcoming anniversary of the massacre.

Moder took to Facebook to express his anger over how the show treated him.

“Well, a predictable butchering by these biased, agenda driven moral ‘gatekeepers’ and the saddest part is, I expected it going into the interview,” Moder wrote.

“The Project, long ago lost it’s integrity, objectivity and fairness, but it was worth it to see the crestfallen look on their faces after the interview and trust me, I gave as good as I got.

“For the record (clears throat) Bryant – The Port Arthur Massacre, will NOT be a conspiracy theorist film NOR a film which is only about Martin Bryant. It will be a balanced, in depth study of the people and event that is based on the FACTS as far as they can be determined.”

Watch the full interview below.

Things get heated when we speak to the producer who wants to make a Port Arthur massacre film #TheProjectTV https://t.co/5Gml6d6P3o

— #TheProjectTV (@theprojecttv) April 25, 2016