Australian mining tycoon and election hopeful Clive Palmer has threatened to sue Rupert Murdoch and accused his estranged wife of "spying".



Palmer's threat to sue concerns an opinion piece published in the Murdoch-owned newspaper The Australian, which questioned whether he is a mining magnate and billionaire.



Palmer accused Murdoch of telling his reporters what to write and said he needed to be brought to account.



"Murdoch will be sued by me today and will be brought to Australia to answer these questions in the Supreme Court," he told the Seven Network's Sunrise program on Thursday.



"It's time this fellow was brought to account, this foreigner who tries to dictate what we do."



Palmer was questioned about his fortune and business dealings, but said he never claimed to be a mining magnate and did not know whether he was a billionaire.



"All I've said is I'm an Australian and I want to stand in the election," he said.



While hitting the breakfast television circuit on Thursday, Palmer also made accusations on the Nine Network's Today show about Murdoch's estranged wife, Wendi Deng.



"You know, Rupert Murdoch's wife Wendi Deng is a Chinese spy, and that's been right across the world," he alleged.



"She's been spying on Rupert for years, giving money back to Chinese intelligence. Read the truth about it.



"She was trained in southern China. I'm telling you the truth, I'm telling you the truth.''



A stunned Today host Karl Stefanovic interrupted Palmer, questioning whether he had "lost the plot".



But Palmer continued: "Wendy Deng is a Chinese spy, that's why Rupert Murdoch got rid of her, and that's the truth. And this guy wants to control Australian politics.



"He wants to control what you think."



If the latest polls are correct, Palmer's party could win the sixth Queensland senate seat.



Palmer is also suing Liberal National Party candidate Mal Brough. He is seeking $355,500 in general damages and $450,000 in aggravated compensation.



Palmer recently claimed Brough asked him to fund a legal campaign that would destroy the reputation of his political rival Peter Slipper - the former House of Representatives speaker standing as an independent for Fisher.



Brough strenuously denied the allegation, saying "there has been inconsistency on this issue from day one from Mr Palmer".



- with AAP