Mining tycoon Clive Palmer is escalating his case against the Australian government to Switzerland’s highest court after an international tribunal rejected his claim of being a foreign investor and ordered him to pay $13.6 million.

Palmer is attempting to challenge Western Australian legislation that was rushed through to block him from claiming about $30 billion in damages in 2020 over a decision to reject his proposed Balmoral South iron ore project in Pilbara – a sum which officials said would have bankrupted the state.

After an unsuccessful bid in the High Court, a Singaporean investment company owned by Palmer brought the matter before the Permanent Court of Arbitration, an intergovernmental organisation.

The case argued breaches against the Asean-Australian-New Zealand free trade agreement.

Foreign investors have the right to claim compensation for law or policy changes that reduce future profits in an international tribunal.

Palmer is an Australian citizen.

He is also the fifth richest in the country with a net wealth of $20.12 billion, according to the Australian Financial Review.

Attorney-General Michelle Rowland said the tribunal unanimously rejected the case yesterday, saying it had no jurisdiction over the dispute, and ordered Palmer to pay the Commonwealth’s costs of $13.6 million.

“Mr Palmer is not a ‘foreign investor’ and is not entitled to any benefits under Australia’s free trade and investment agreements,” she said in a statement.

“I am pleased that the Tribunal has accepted Australia’s arguments and rejected Mr Palmer’s claim.

“Australia should never have had to spend two years and over $13 million defending an investor-state claim brought by an Australian national.”

Rowland said she hoped Palmer would withdraw his remaining three international claims against Australia, while Premier Roger Cook said he hoped the decision would “finally close the book on this long-running saga”.

But a day later, the billionaire launched a new case in Switzerland. 

Palmer has announced that he will be challenging the international tribunal’s decision in Switzerland’s Federal Supreme Court. 

He said this was the “next step in the journey to achieve justice in the matter, hopeful of the final arbiter taking an opposite view to that of the tribunal”.