A new secret recording has emerged of Pauline Hanson, with the One Nation leader appearing worried the alleged donation of a light aircraft would be revealed, months before it became a public controversy.

The recording is of a phone conversation between the party's former treasurer Ian Nelson and Senator Hanson on November 20 last year.

It is the second covert recording to emerge from within One Nation in the last fortnight.

Mr Nelson made the recording and provided it to the 7.30 program because he claims it proves Senator Hanson was aware the plane was donated and wanted it kept quiet.

"I think she wanted it not made public and I'm not quite sure to this day why," Mr Nelson said.

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Senator Hanson dismissed questions about the new recording as she was entering Parliament House in Canberra this morning.

"I cannot believe you would ask me some stupid questions like that," Senator Hanson said.

"I have had a gentleman who's been shot dead in the electorate, we have people homeless in the cold weather, we have the state of the country, and you're worried about that from some disgruntled people?

"I think it's disgusting."

'Who knows that he paid the money?'

The Australian Electoral Commission (AEC) is investigating whether One Nation breached any disclosure laws, after Mr Nelson's allegation last month on Four Corners that property developer Bill McNee paid for the aircraft used during the 2016 election campaign.

Mr McNee has denied donating the plane, and One Nation has denied breaching electoral laws by not declaring the donation.

However, Mr Nelson claims the phone recording of Senator Hanson contradicts this and has provided it after being compelled to by the AEC.

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During the conversation in November, Senator Hanson asked Mr Nelson how a newspaper journalist found out about Mr McNee's financial contributions.

"We've got word there's a story coming out in The Australian [newspaper] tomorrow and they've actually been told that Bill McNee actually donated the money to pay up front for the office for the year and for the plane," she said.

"Who the bloody hell did they get that off?" Mr Nelson replied.

Senator Hanson responded: "They've already rung Bill and asked him and he said, 'Yep, but I've donated to a lot of parties'."

Then the pair discussed which One Nation insider could have leaked the information.

Senator Hanson: "Who knows Bill's name? No-one, we always kept it very quiet. She continues: Who knows that he paid the money upfront for the office?" Mr Nelson: "I have no idea." Senator Hanson: "There was only the four of us who knew. It was tight-knit."

The four believed to be referred to are Senator Hanson, her chief of staff James Ashby, Mr Nelson and another former staff member, Saraya Beric.

'I'm not happy ... but everything's above board'

Both Mr Nelson and Ms Beric have spoken publicly about what they see as their unfair treatment by One Nation.

But the party claims they are disgruntled former staff members who are bitter about being passed over for key roles.

On the recording, Senator Hanson blames Ms Beric for the leak.

"I have to see what else she's said to them about Bill, but everything was above board because that was all recorded with the AEC and donations and it was all correctly done," Senator Hanson said.

"And if it wasn't, it's going to come back with her because she was secretary of the party.

"I'm not happy but I've got nothing to worry about because everything is above board."

7.30 has spoken with Ms Beric who has denied being the source of the newspaper leak.

During the conversation Mr Nelson promised Senator Hanson he would not speak to the media, including the ABC.

"I promised you that, I promised James and I'm a man of my word. They [the media] drive me crazy and I haven't said a word to anyone," he said at the time.

Mr Nelson said he was now breaking that promise so he could defend himself and Ms Beric from public attacks.

'We're pushing back'

Former One Nation treasurer Ian Nelson (r) with media advisor James Ashby (l) and Pauline Hanson (c). ( ABC News: Michael Atkin )

Last week One Nation accused the two former staffers of orchestrating a campaign against the party, including leaking another covert recording.

Mr Nelson has rejected being involved.

"It's time for me to push back because Saraya and I were happy to walk away from the whole thing but James Ashby, Pauline Hanson keep coming out on national television … and just bagging us time after time and it's time it stopped," he said.

"We're pushing back."

In a statement Senator Hanson said she has not lied to the public about Mr McNee's donations and "there are no admissions in the recordings that Senator Hanson needs to be concerned about".

"If Senator Hanson said at the time that Mr McNee was paying for the aeroplane by way of donation to the party then that must have been his intention," the statement said.

"If Mr McNee subsequently decided to give the aeroplane to Mr Ashby then that is a matter for Mr McNee.

"Saraya Beric is the subject of a complaint to police for breaches of the Listening Devices Act. Similar complaints will be made about Ian Nelson."

Mr McNee also declined to comment further while the AEC investigation was ongoing, saying he has made it clear he did not donate the plane.

"There's an AEC investigation going on at the moment and all of that will be revealed," he said.

"We've been up front and honest with respect to that matter and we'll let it take its course."

You can watch the story tonight on the ABC's 7.30 program.