Prince Charles is not quiet when it comes to giving his views on the big issues of the day. On 23 May, the heir to the throne defended Britain's small farmers as “the backbone of our rural communities”.

The prince stopped short of criticising the government – but his comments came as Boris Johnson offered a post-Brexit trade deal with Australia that critics warn could have a “massive” detrimental impact on British farms as Australian meat floods the market.

But openDemocracy can reveal that Charles himself is advised by a man who stands to gain from the Australian deal.

Hedge fund billionaire, and one time Australian army captain, Michael Hintze has “significant investments” in the country's agricultural sector. As well as donating to the Conservatives, Vote Leave and the ruling Australian Liberal party, Hintze is a long-standing adviser to Prince Charles.

He has been listed as one of Australia’s richest individuals, while his company MH Premium Farms holds more than 70,000 hectares of land across eastern Australia. Its website boasts: “The group now owns in excess of 41 properties located strategically across several climatic regions with operations in all traditional agricultural enterprises.”

It has been predicted that if the free trade deal goes ahead then Australian beef exports could see up to a tenfold increase.

National Farmers’ Union president Minette Batters warned: “A tariff-free trade deal with Australia will jeopardise our own farming industry and will cause the demise of many, many beef and sheep farms throughout the UK.”

Hintze could potentially be one of the biggest winners from the deal, given his financial stake in Australia's agricultural sector.

He has been an adviser to The Prince’s Council since 2014 and has fostered a close relationship with Charles and Camilla.

The prince and the duchess of Cornwall have even visited Hintze in Australia, enjoying a “secret” three-day visit at his sprawling estate, 285 miles southwest of Sydney, ahead of the 2018 Commonwealth Games.

The billionaire enjoys strong political links in both his native and adopted homelands. He has been described as the “Godfather of Tory donors”, having given millions to the Conservative Party in donations and loans.

In 2019, openDemocracy revealed that Hintze was part of the secretive Leader’s Group, an elite Tory dining club that enjoys direct access to Boris Johnson and raises vast amounts for the party’s election campaigns.

He was knighted in 2013, when David Cameron was prime minister and went on to donate £200,000 to Vote Leave during the Brexit referendum campaign.

Hintze is also close to Tony Abbott, the former Australian prime minister who was appointed as a trade adviser by international trade secretary Liz Truss last year.

Opposition parties condemned the appointment saying he was “the wrong” choice “on every level” for the unpaid role, amid criticisms over previous comments about women, LGBT people and climate change.

Hintze has donated to Abbott’s Liberal Party and has previously helped pay for his travel to the UK and US.

In 2017, Hintze was said to be in front row of the audience when Abbott gave a “loopy” speech to the Global Warming Policy Foundation, in which he declared “a gradual lift in global temperatures” might “be beneficial”. The Westminster-based organisation was set up by Nigel Lawson, the climate sceptic former UK chancellor, and pushes back against policies to tackle climate change.

The close relationship between Prince Charles and Hintze was apparent after claims that the hedge fund boss spent up to $3m renovating his New South Wales property in anticipation of Prince Charles’s visit in 2018.

The retreat has been described as “one of finest estates in the country” and was reportedly purchased by Hintze for £10.3m in 2016.

But although a royal spokesperson initially said it would come at “no cost to the taxpayer”, documents show that Australian taxpayers footed the entourage’s $18,916 bill.

As well as being personally close, Prince Charles and Hintze have also employed some of the same staff. In 2017, Charles's former private secretary Michael Peat was appointed as interim chair of Hintze's hedge fund, CQS.

With responsibility for the prince’s finances, Peat reportedly made Charles much richer during his time as principle private secretary. When he resigned in 2011 he said he “will be forever in His Royal Highness’ debt”.

Hintze’s businesses have come under scrutiny over their tax affairs. The Mirror reported that his UK-based investment firm, CQS Management Limited, had turned over more than £78.5m in 2011, but only paid £6,192 in corporation tax.

A company spokesman at the time said: “We are a significant UK taxpayer.”