It all started in 2015 with a ride to the airport. I was driving from Washington DC to make a flight overseas when I heard a report on the radio of yet another mass shooting in America.

As details of the killings were being broadcast, I happened to be driving through Fairfax, Virginia, right past the headquarters of the National Rifle Association of America.

I glanced at the building and wondered, "What are they saying in there about what I'm hearing out here?"

The NRA's public reaction on a massacre tend to follow a pattern: stay quiet for as long as possible and then, if the media persists, attack them as anti-gun activists, even "silent enablers" of the tragedy.

So, I decided to find a way to get into the organisation to hear for myself what America's most powerful gun lobby group says behind closed doors about such events.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 52 seconds 52 s James Ashby and Steve Dickson speak to a fake gun lobbyist ( Al Jazeera )

NRA's 'vehement' opposition to Australian gun laws

How does the NRA formulate corporate strategies to manage the media in the wake of a mass shooting?

What discussions take place around the pressuring of members of Congress to follow the NRA's pro-gun messaging?

Is there dissent within the organisation over their promotion of the AR-15 assault rifle, a firearm that's become a weapon of choice for mass killers in America and which was used in both the Port Arthur massacre and the recent mass killing in Christchurch?

It had become clear to me that the NRA was fervently opposed to Australia's National Firearms Agreement, the gun-control legislation introduced following the 1996 Port Arthur massacre.

The NRA frequently attacked the law and those within the US who admired it.

When Hillary Clinton and Barack Obama pointed to Australia's gun legislation, they were accused by the NRA of being "gun-grabbers", intent on repealing America's Second Amendment — the right of US citizens to "keep and bear arms".

It seemed logical to me that if the NRA was so vehemently opposed to the Australian laws, they'd most likely be pleased to hear from an Australian who shared their views.

So, with guidance from media lawyers in Australia, the United States and the United Kingdom, I created a pro-gun group which I called Gun Rights Australia, and I appointed Rodger Muller to be its founder and president.

The website created for Gun Rights Australia described Rodger Muller as a "man of action". ( Supplied )

His mission was to befriend officials within the NRA by expressing concern about Australia's laws being too strict.

He was to climb as high as he could within the NRA's executive ranks and to record unguarded discussions with people inside the organisation using concealed cameras and microphones.

I hired a second undercover reporter, Diana Armata*, who presented herself as Mr Muller's communications director.

She constructed and maintained the Gun Rights Australia website and helped build a layered back-story for Mr Muller which involved a series of videos filmed in Australia and the US in which he called for a "sensible debate" about the roll-back of the post-Port Arthur laws.

A screenshot from the Gun Rights Australia website, created for the Al Jazeera investigation. ( Supplied )

I wanted visitors to the Gun Rights Australia website to see that Mr Muller had been active as a gun advocate for years — and the lengthy history of videos, articles and other postings seemed to show that he had been.

With the NRA appearing to accept Mr Muller as a man who shared their views, he and Ms Armata spent more than two years accumulating hundreds of hours of hidden camera footage and briefing me on the many conversations they had conducted with gun lobby officials within the US.

Details on the NRA's playbook for how to manipulate the media, how to pressure members of Congress, and how to downplay the horror of gun deaths began to emerge.

Mr Muller even learnt that some NRA officials are so afraid of the anti-gun movement that they are bracing for protestors to storm their offices and kill them.

Approaching One Nation

The film's connection to One Nation only began in 2018, after I read an article in a Queensland newspaper claiming that Australia's One Nation party had received funding from an NRA-affiliated organisation within Australia.

The article led me to wonder whether any direct connection existed between One Nation and the NRA, so I asked Mr Muller to visit the party to find out.

Mr Muller approached One Nation leader Pauline Hanson's chief of staff, James Ashby, and mentioned the "friends" he had developed within the National Rifle Association.

Instead of confirming a connection of his own, Mr Ashby asked to meet Mr Muller's contacts — people, he later said that he hoped might provide millions of dollars of funding to the political party.

Steve Dickson (left), pictured with James Ashby, hoped the National Rifle Association might "throw 10 million US dollars" at One Nation. ( Supplied: Al Jazeera )

Mr Muller was urged by Mr Ashby to contact Steve Dickson, One Nation's Queensland leader and a Senate candidate for the upcoming federal election.

Mr Dickson had been instrumental in writing One Nation's 21-point gun policy which included a softening of some restrictions currently imposed under the National Firearms Agreement.

In a meeting at One Nation's Brisbane headquarters, Mr Dickson made clear the party's intentions to increase its power within Australia with the use of US gun lobby cash.

He told Mr Muller that he was hoping that the NRA might "throw 10 million US dollars at us" which would help him win "a heap of seats, plus a shitload of seats in the Senate".

Mr Dickson and Mr Ashby bought tickets to the US and booked hotel rooms in Washington in preparation for a week of key meetings with gun lobby officials.

Mr Muller and Ms Armata were there to meet them with their concealed cameras primed and ready to roll.

Over the course of that week, both Mr Ashby and Mr Dickson asked Mr Muller and Ms Armata to keep details of the One Nation meetings secret.

Mr Dickson told Mr Muller: "Anything you say or write, be prepared to read it on the front page of the paper."

How right he was.

*Not her real name.

Peter Charley is executive producer of Al Jazeera's Investigative Unit based in Washington, DC

Watch the second part of the Al Jazeera investigation at 8pm on Thursday on ABC TV, or watch the first part on iview.