A retired police officer who sat across a table from Martin Bryant after the Port Arthur massacre has labelled One Nation leader Pauline Hanson's comments as outlandish and very disrespectful to victims.
Former Tasmania Police Detective Inspectors John Warren and Ross Payne interviewed Bryant.
Now retired and living in Queensland, Mr Warren said the senator's comments were made without any factual evidence to support the statements.
"We had a taskforce set up after the event which probably ran for somewhere near six months and every part of that incident was investigated," he said.
Senator Hanson was captured on video by an undercover Al Jazeera journalist saying there were "a lot of questions" about the Port Arthur massacre that left 35 people dead in 1996.
"An MP said it would actually take a massacre in Tasmania to change the gun laws in Australia," Senator Hanson said.
"Haven't you heard that?" Senator Hanson asked Al Jazeera's Rodger Muller.
The journalist pretended to be a representative of a fake lobby group, Gun Rights Australia.
"Have a look at it. It was said on the floor of Parliament. I've read a lot and I have read the book on it, Port Arthur. A lot of questions there," Senator Hanson said.
Fierce backlash about the comments led to Senator Hanson making a public statement in Brisbane on Thursday. She claimed she was taken out of context and she believed Bryant was solely responsible for Port Arthur.
Mr Warren said he was quite astounded and disappointed that a federal politician could make such outlandish comments without having any evidence to back it up.
"What these conspirators can't seem to comprehend is there were a number of victims who were wounded and actually survived who saw Brian do it, so I would've thought that anyone with an ounce of commonsense would think, 'hang on, how can there be a conspiracy there'," he said.
Tasmania Police Association president and former Special Operations Group member Colin Riley said the member of Parliament's comments were ill-informed, unnecessary, and categorically wrong.
Mr Riley was involved in the response to, and investigation of, the Port Arthur massacre. He said he would invite Senator Hanson to the site so he can walk her through what happened.
Prime Minister Scott Morrison said he was shocked by the comments.
Tasmanian premier Will Hodgman and opposition leader Rebecca White labelled the comments appalling, ignorant and offensive.
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