Political lobbyist and One Nation donor Michael Kauter with Pauline Hanson. In March Mr Kauter was named as Senator Hanson's single biggest financial donor. On Friday, he denied that had any influence on Hanson's senate speech on behalf of his client. "No one tells Pauline Hanson what to do ... she was not paid to do our bidding but I brought the issue to her because I thought it was one she would be interested in ... and I am far from the only lobbyist who has donated money to the party," Mr Kauter said. Mr Kauter has accused a company Ms MacSween is an investor in of owing his business a six-figure sum after his firm, Strategic Political Counsel, was specifically enlisted to win the support of Hanson to apply political pressure. Ms MacSween confirmed she was an investor in her brother-in-law Michael Lehman's company Nutraceutical and Natural Products (NNP).

In 2010 NNP was awarded a contract to "commercialise" PlantZap, a process that claims to reduce the sugar content of sugarcane products by up to 50 per cent without affecting the taste. Prue MacSween, Michael Lehman and Federal Senator Pauline Hanson. It was predicted PlantZap could turn into a business worth hundreds of millions and be a boon for cane farmers, as well as a money spinner for Ms MacSween and Mr Lehman. Mr Kauter, who admits his style is "unorthodox" but says he "punches above my weight", has cultivated a close relationship with key political figures on the far right, including Barnaby Joyce and Hanson. He and his physician husband David Gracey are also close to radio kingpin Alan Jones. Mr Kauter, who as a school student handed out leaflets for One Nation in Toowoomba, is a former deputy director of the Nationals, though he ended up in a dispute with the party last year over a sponsorship deal. He is also a key lobbyist for the tobacco industry and Adani.

In March it emerged he was also one of the biggest donors to One Nation, his SPC firm donating $30,000 to the Queensland branch, making Kauter the single largest donor over a six-month period. The donation was more than a third of the party's total income. Senator Hanson's chief of staff James Ashby denied these donations meant Mr Kauter had any influence over Hanson's political agenda, and said the $30,000 was for two tickets to a fundraiser held in outback Queensland. "Nothing untoward has gone on," Mr Ashby said on Friday, providing a letter claiming it was a sugar cane farmer who brought the PlantZap matter to Senator Hanson's attention. However, Mr Kauter later said he had made the first contact with the Senator's office on behalf of his PlantZap clients, Mr Lehman and Ms MacSween, facilitating meetings with them in her office. Mr Kauter hired Sydney media consultant Juliet Potter a fortnight ago to approach Ms MacSween to resolve the issue of NNP's unpaid bills from the PlantZap contract.

Ms MacSween said she was not an "officer" of the company which hired Mr Kauter's firm, just an investor, and therefore was not responsible for, or privy to, the company's operational issues, including its agreement with Strategic Political Counsel. Ms Potter sent Ms MacSween a text saying: "As you are aware, legally there is no point in pursuing the debt, but as far as a media story goes, given the high profile and the political names involved, there is a story here." Ms MacSween saw red and lodged a complaint with Surry Hills police, who questioned Ms Potter but took no further action. Ms MacSween's lawyers also issued Ms Potter with a legal warning, saying Ms MacSween felt "harassed, menaced and threatened by your text messages and is fearful and worried for her reputation and goodwill as well as her personal financial security". On June 27, Mr Kauter and Mr Lehmann signed a $25,000-a-month, six-month contract for PlantBiz. However, NNP's Swiss entity was liquidated the next day, though Mr Lehman's locally registered company of the same name continues to trade.

Both Mr Lehman and Ms MacSween have denied any knowledge that the liquidation was so imminent at the time their company entered the agreement. Nearly two months later and after Ms MacSween stumped up $15,000 to partially cover Mr Kauter's first invoice, which she said was done "as a favour for my brother in law", Senator Hanson launched her stinging attack on the Queensland government on NNP's behalf. This was soon followed by an appearance of Mr Lehman on Alan Jones' Sky News TV show, which Ms MacSween says she orchestrated. Mr Kauter denied Jones received any payment for the appearance. In a written response to Mr Kauter's claims, Mr Lehman told PS: "I would not have entered into the contract with Strategic Political Counsel if I had known the company was being wound up as I was under the impression at the time of signing that the liquidation issue had been resolved." Mr Lehman added he was in dispute with SPC over what he claimed was the company's "poor performance" and "failure to deliver services, as instructed on their appointment". Mr Lehman also claimed he had been hit with "excessive" travel charges.