Pauline Hanson’s One Nation has been connected to supporters of the Port Arthur conspiracy theory since before the party was formed in 1997, despite repeated assurances from the Queensland senator that she had never believed the theory.

According to a Queensland political historian, it would take “a lot of good faith” to assume that Hanson has not been aware that those supporting the conspiracy theory had found safe harbour in One Nation over the past 20 years.

Hanson was forced to publicly disavow the theory last week after an investigation by al-Jazeera aired secretly recorded footage of her appearing to promote the conspiracy, telling the undercover reporter that she had “read the book on it” and there were “a lot of questions there”.

It is the second time One Nation has been connected to the conspiracy theory in two years, following the sacking of a Queensland election candidate in 2017 who referred to it on a blog post.

It is also the second time Hanson has had to distance herself from the theory, after a furore over suggestions made in a small publication in 2001 prompted her to tell the ABC that while she thought the gun reforms were “a knee jerk reaction by the government” she did “not support any conspiracy theories regarding Port Arthur”.

Conspiracy theories around the 1996 massacre, in which 35 people were killed by a single gunman, propose that the event was arranged in order to bring about Australia’s tough gun laws, which were introduced by the Howard government within 12 days of the tragedy.

The hurt caused by these theories is often raised by survivors and management of the Port Arthur historic site as a reason they are reluctant to talk to media about the tragedy, because every story inevitably brings another flurry of correspondence from those who believe it to have been a set-up.

Those who promote the theory often also argue against Australia’s gun laws and cite a prophetic remark by the former NSW premier Barry Unsworth, who said on leaving a 1987 gun summit in which Tasmania had been the hold-out against stronger laws: “It will take a massacre in Tasmania before we get gun reform.”

In secretly recorded conversations with the undercover al-Jazeera journalist, Hanson mentioned Unsworth’s remark, urging the reporter, who was posing as a member of an Australian gun lobby group, to “have a look at it”.

She said: “Those shots, those were precision shots. Check the number out. I have read a lot and I have read the book on it, [on] Port Arthur. A lot of questions there.”

Three days after the two-day documentary aired on the ABC, Hanson told Channel Nine’s Today Show she had “never said at all that it was a conspiracy theory” and accused al-Jazeera of dubbing over the questions to her to misrepresent her answer.

She said the light blue, “not very big” book had been sent to her after she left parliament, having lost her seat in 1998. The book she was referring to is believed to be Deadly Deception at Port Arthur, self-published by Joe Vialls.

She also “categorically” denied any plan to water down Australia’s gun laws, despite senior One Nation figures being recorded talking about seeking millions in political donations from the National Rifle Association to do so, and despite the party’s current policy platform which proposes a number of small changes that, taken together, would weaken firearm laws.

Hanson told Channel Nine that, had she believed the theory, she would have used her position in the House of Representatives at the time to raise the issue on the floor of parliament. She was elected to the federal seat of Oxley 26 days before the Port Arthur massacre.

That is exactly what Vialls hoped she would do.

In one version of the text, which was serialised by a number of rightwing news sheets in the late 1990s as well as being self-published, Vialls writes that perhaps “the independent Honourable Member for Oxley could find the time to ask the Prime Minister a few meaningful questions in Parliament” about the theories he raised.

One of those who published Vialls’ work in the rightwing street press was Tony Pitt.

Pitt was a founding member of a number of short-lived fringe political parties and organisations including the Confederate Action Party of Australia. It was registered with the AEC for 11 months in the early 1990s – long enough to field candidates in the 1992 Queensland state election and the federal election in March 1993.

In 1992 it netted about 1.3% of the statewide vote – more than either the Democrats or the Greens. In the 12 seats where it fielded a candidate, it was the leading minor party, polling as high as 16.2% in Maryborough.

‘Snatching firearms from legally entitled owners’

Pitt was the candidate in Maryborough and went on to be the convenor of the Hervey Bay branch of One Nation, and was also associated with its Maryborough branch.

Another Confederate Action Party candidate, Bruce Whiteside, went on to found the Pauline Hanson Support Movement, an organisation that was later tied up in Hanson’s 2003 conviction and jailing for electoral fraud. The conviction was overturned on appeal later that year.

One of the people who was party to the civil action which led to the criminal fraud investigation was David Summers, who was disendorsed by the party as a candidate for the seat of Noosa in the 1998 state election. Summers edited a fringe leaflet called Exposure Magazine, which also published Vialls’ theories.

Chris Salisbury, a political historian at the University of Queensland, says grievances about the gun laws and far-right groups such as the Confederate Action Party and the Australian League of Rights were tied up in the foundation of One Nation.

“[One Nation] formed in the wake of the Port Arthur massacre and the introduction of the national firearms agreement,” he said. “Pauline Hanson herself phrased it at the time as the snatching of firearms from legally entitled gun owners.”

Salisbury said that people who belonged to regional fringe politics, including some who subscribed to the Port Arthur conspiracy and similar theories, were “part of that broader anti-establishment and voter-grievance movement that has really provided much of the support for One Nation for so long”.

One Nation’s co-founder, David Oldfield, met some fringe and gun rights groups – although not those publicly espousing the conspiracy theory – in the early days of the party.

“You would really need to I guess take a lot of good faith to think that [Hanson] hasn’t been aware and been within very close contact of these ideas circulating in and around her party over the course of 20 years,” he said. “But she will of course continue to deny it and I think, for many, we are probably right to be sceptical.”

Hanson’s own position on the conspiracy theory, which she has publicly denied supporting despite comments aired on the al-Jazeera report, was “something a lot of people should ponder leading up to the election”, Salisbury said.

“I have no doubt a lot of the party’s adherent supporters will see this as again another episode of Pauline being persecuted. It won’t do anything to change their minds,” he said. “But I think for a lot of the rest of Australia it’s reasonable to assume that over the course of 20 years, along with the plethora of other contentious and objectionable issues that have gravitated towards One Nation or emanated out of it, this Port Arthur conspiracy has continued to raise its head.”

Hanson has maintained that the undercover investigation of her and her party by al-Jazeera was entrapment and amounted to foreign interference in an Australian political party.

Asked if she would apologise to the victims of the Port Arthur massacre for her remarks, Hanson told Channel Nine the blame lay with al-Jazeera.

“My comments were made at a dinner table, never made publicly, it’s not my doing to have exposed this ... it was al-Jazeera and an undercover agent,” she said. “I am sorry for these people, I really am genuinely sorry for them. They shouldn’t have to go through this again.”