One Nation leader Pauline Hanson has been caught on hidden camera appearing to insinuate the 1996 Port Arthur massacre was a government conspiracy.

The footage, released by Al Jazeera as part of a three-year-long undercover investigation, reportedly shows her saying she has “a lot of questions” about Port Arthur.

“An MP said it would actually take a massacre in Tasmania to change the gun laws in Australia,” Senator Hanson tells Al Jazeera reporter Rodger Muller.

“Haven’t you heard that? Have a look at it. It was said on the floor of parliament.”

More undercover footage appears to show Senator Hanson discussing other conspiracy theories with her chief of staff James Ashby.

“That whole September 11 thing, too,” Mr Ashby says just after the comments about Port Arthur.

Camera Icon A screenshot of Pauline Hanson and James Ashby from the video. Credit: Al Jazeera/ABC

“Those shots. They were precision shots,” Senator Hanson says.

“Check the number out. I’ve read a lot and I have read the book on it, Port Arthur. A lot of questions there.”

The shocking footage follows a national uproar yesterday after Muller’s investigation released video footage of Mr Ashby and Queensland One Nation Senator Steve Dickson discussing the possibility of getting funding from the National Rifle Association in the US to weaken Australia’s gun laws.

Senator Dickson and Mr Ashby claimed they were drunk when the video was filmed.

But Prime Minister Scott Morrison urged Australians to abandon One Nation, saying being drunk was no excuse for its party officials talking about asking the American gun lobby for $US20 million.

“Being drunk is no excuse for trading away Australia’s gun laws to foreign bidders,” the prime minister told reporters in Sydney today.

In Al Jazeera’s footage, Mr Dickson says One Nation could get the government “by the balls” through holding the balance of power in both houses if they could get millions in funding.

That would allow them to weaken Australia’s gun laws, a point they raised with powerful lobby groups in Washington DC including the National Rifle Association.

Senator Hanson broke her silence on Wednesday, saying she was shocked and disgusted with the “hit piece” by Qatari TV network Al Jazeera.

“A Qatari government organisation should not be targeting Australian political parties. This has been referred to ASIO,” she tweeted.

The One Nation leader has been suffering from a tick bite on her face for the past week but is expected to front the media on Thursday.

Mr Morrison urged One Nation voters to support the coalition, criticising minor parties’ ability to pursue their agenda.

“These are not parties of government, they are parties of grievance,” he said.

Labor leader Bill Shorten repeated his assertion the prime minister needs to back up his condemnation of One Nation by putting them last on Liberal how-to- vote cards.

Australian Conservatives senator Cory Bernardi said he wasn’t falling for the “smokescreen” of blaming a foreign media organisation.

“Pauline Hanson needs to give these two blokes the flick,” he told Sky News.

Nationals cabinet minister Matt Canavan said the revelations had exposed One Nation as “absolute frauds”.

Mr Ashby said the pair spoke only with undercover Al Jazeera reporter Rodger Muller about the potential $US20 million in donations.

Mr Muller posed as the head of fake lobby group Guns Rights Australia and initiated the One Nation meetings with the NRA.

Mr Ashby accused Mr Muller, who is Australian, of being a “Middle Eastern spy”.