The Clean Energy Regulator has confirmed it received a payment from Clive Palmer’s company Queensland Nickel for $6.8 million.

Queensland Nickel has paid its overdue carbon tax debt of nearly $7 million, but the company owned by federal MP and mining magnate Clive Palmer is not out of the woods just yet.

The Clean Energy Regulator has confirmed that on Tuesday it received a payment from Mr Palmer’s company Queensland Nickel for $6.8 million.

The payment was for the company’s outstanding $6.1 million carbon tax debt to June 2013, plus 20 per cent interest a year through to the end of the year.

This clarification from the regulator backs Mr Palmer’s insistence earlier on Tuesday that he’d already authorised the payment. But the regulator also said the amount it received did not include the interest accrued on the debt since December 31, and Queensland Nickel still had more cash to cough up.

“A further debt in the amount of $2.27 million fell due in February 2014 at the end of the final surrender period,” a spokesperson for the regulator told AAP in a statement on Tuesday evening.

“The Clean Energy Regulator will continue to pursue the debts using appropriate means, including payment plans and court proceedings.”

Queensland Nickel also confirmed it paid around $6,815,000 to the regulator on Tuesday, reducing its carbon tax liability as of December 31 to zero.

A statement from the company said as an exporter trading in international commodity markets, Queensland Nickel could not pass on the costs of the carbon tax to its customers.

“Queensland Nickel’s international competitors are not plagued by the same high level of carbon pricing,” the statement read.

Mr Palmer earlier said the payment was authorised to be made this week, well before the April 5 deadline imposed by the regulator.

But he did not know exactly when the authorisation was made, but denied it was done at the very last minute.

“Do you pay your tax months in advance?” he told reporters in Perth on Tuesday.

“Most people will pay their tax just before it’s due and that’s what our company’s decided to do.”

He said Queensland Nickel would continue with its High Court challenge to the legal validity of the carbon pricing scheme.