Federal MP Clive Palmer says his mining company Queensland Nickel has paid its multi-million-dollar carbon tax bill before the Clean Energy Regulator's April 5 deadline.

Mr Palmer says newspaper reports suggesting the Clean Energy Regulator (CER) was preparing to shut down Queensland Nickel over the unpaid bill are false.

"The Clean Energy [Regulator] wrote to us and said we had until the 5th of April," Mr Palmer told the ABC.

"We wrote back and said we would [pay]. It's well before the due date of the 5th of April."

A statement from Queensland Nickel said: "In response to the invitation by the Clean Energy Regulator, on Tuesday, 1 April 2014 Queensland Nickel paid the amount of $6,815,046.22 to the Clean Energy Regulator thereby reducing the company’s carbon tax liability as at 31 December 2013 to zero."

Mr Palmer says Queensland Nickel is happy to comply with the carbon pricing scheme.

He says his companies are "good, law-abiding citizens ... and like all Australian citizens, we're doing the right thing".

Queensland Nickel's also owes $2.3 million for the first half of the current financial year.

The Clean Energy Regulator cannot confirm whether it has received Queensland Nickel's payment at this stage.

The regulator had engaged the Australian Government Solicitor to pursue the unpaid bills of Queensland Nickel and three other companies, but no formal legal action has been started.

Queensland Nickel will continue its High Court challenge against the legal validity of the carbon pricing scheme.

"Our advice is [that] it's not a legal tax, regardless of policy issues," Mr Palmer said.

"We're waiting for the hearing and when it happens, it'll be determined whether or not it's a legal tax."

Mr Palmer says it is Queensland Nickel's board of directors pursuing the legal challenge to the scheme, not him.

"They decide what the company's corporate position will be," he said.

'I don't owe any tax to anybody'

The MP for Fairfax has lashed out at The Australian newspaper for reporting that the CER was preparing to close down the company over the unpaid bill.

"You've got Rupert Murdoch and his cohorts writing stories which are not true, but they write them nonetheless," he said.

"They're a great bunch of fictional boys.

"All these stories are as though it's Clive Palmer. I don't owe any tax to anybody."

Mr Palmer says the Australian Tax Office owed him money after his last personal tax return.

"The tax department gave me a bit back last year as a refund because I paid too much tax. Millions of dollars too much, but they still refunded it."

Mr Palmer has also defended the amount of money his political party is spending on advertising in Western Australia ahead of Saturday's re-run of the senate election.

West Australians are voting again after more than 1,000 senate ballot papers went missing after the September poll.

The Palmer United Party is hoping to win a seat in Western Australia to join the Queensland and Tasmanian senators elected in September.

"People back in the 1960s said, 'Money can't buy you love', and I think they're right," he said.

"It's the message that matters in politics, not how much you spend."