Asked on Friday whether a ''sham'' port services agreement had been cobbled together, as alleged by his opponents, Mr Palmer replied: ''That's just untrue, completely untrue.

''The Chinese are trying to prejudice the courts against us. The reality is that the weaker their case gets, the more publicity they need.''

The latest claims were made by Chinese-owned Sino Iron and Citic Pacific in documents lodged before the Queensland Supreme Court this week and turn on cheques drawn from a disputed port administration account.

The federal MP and head of the Palmer United Palmer said the money was his to disburse but Sino Iron and Citic claim the payments benefiting Palmer interests were ''dishonest and fraudulent'' because they did not relate to port administration.

The timing of the two contested withdrawals which Mr Palmer allegedly authorised from the port account were made in the run-up to last year's federal election campaign.

A $10 million payment went to a company controlled by Mr Palmer, Cosmo Developments Pty Ltd, while a $2 million payment went to Media Circus in Brisbane, which booked campaign advertising for the PUP.

The Chinese side claims neither Media Circus nor Cosmo was ''engaged in the provision, supply or arrangement of … management services'' at the Cape Preston port in WA, where the Sino Iron project is gearing up.

It further alleges that a port management services agreement [PMSA] ''executed'' by Mr Palmer, and dated June last year, is a ''sham transaction'' and that Mr Palmer's own executive with responsibility for the port, Paul Robinson, did not see it until two months ago.

''Robinson, notwithstanding his capacity as chief executive officer within [Mr Palmer's company] Mineralogy responsible for the Port, did not see a copy of the PMSA until the weekend of 10-11 May 2014, some 11½ months after its purported creation,'' Sino Iron alleges in its statement of claim.

Mr Palmer said on Friday Mr Robinson would not have seen the document because ''all he does is operate the port, he is not a director of the company'' and drew an analogy with what might be known by ''your janitor downstairs running your airconditioning''.

He also denied the Chinese allegation that he had other signatories to the disputed Port Preston account removed, leaving himself the sole signatory. ''That's just rubbish,'' he said. ''The accountant left in WA was transferred to our office in Queensland, simple as that. People in Western Australia couldn't sign the cheques because they were 5000 miles away. What about Fairfax, who signs their cheques? What rubbish.''

Mr Palmer has been embroiled in legal action with Sino Iron and Citic Pacific for several years over the agreement he struck with them to mine magnetite iron ore from two sub-leases held by Mineralogy near Cape Preston. The legal dispute erupted after the two sides fell out over the royalties allegedly owed by Citic Pacific to Mineralogy.

Citic Pacific's president Zhang Jijing reportedly said the industry benchmarks used to calculate the payments needed to be recalculated after the original system of benchmark prices was replaced by spot pricing. Mr Palmer has disputed the need to change the calculations for the royalty payments.