Wellington - New Zealand Foreign Minister Winston Peters Thursday challenged the country's Serious Fraud Office to prosecute him as a political row over a donation he received from a wealthy businessman continued to rage.

Peters issued a statement challenging the office to charge him, saying it had been "creeping around back doors dropping hints and providing media speculation but not finding any evidence of wrongdoing or illegality" on his part.

"I am prepared to wait on the court steps for them and if they don't turn up they can go away for ever," he said.

Prime Minister Helen Clark, who has refused calls to sack Peters, cast herself into the centre of the row when she revealed for the first time that businessman Owen Glenn had told her about the 100,0000-New-Zealand-dollar (70,000-US-dollar) donation in February.

Peters persistently denied receiving the money until last month when he said that his attorney had just informed him about the donation which had gone anonymously into a trust fund to meet fees for a legal action.

Clark said that Peters consistently denied getting the money when she questioned him. Faced with conflicting statements by the two men, she accepted Peters' word as an honourable member of parliament in line with the parliamentary convention, she told reporters.

Opposition politicians accused Clark of concealing the information in order to preserve her 9-year-old minority government, which is trailing in opinion polls as it faces an election by mid-November.

Peters' nationalist New Zealand First party agreed to support Clark's government after the last election in 2005 in exchange for him getting the foreign affairs portfolio.

Rodney Hide, leader of the free market ACT party, said Clark had put retaining power ahead of ethics, and John Key, who leads the main opposition conservative National Party, said Clark's "stunning revelation" left her with a lot of explaining to do.

Clark said she was standing by Peters, pending the result of an inquiry into the affair by Parliament's powerful privileges committee, which is considering Hide's complaint that Peters did not declare Glenn's donation as he was obliged to do.

Glenn, an expatriate billionaire New Zealander who lobbied to be appointed the country's honorary consul to Monaco where he lives, told the committee in a letter released on Wednesday that Peters had asked him for a donation and subsequently thanked him.

Peters continued to deny that, telling the committee that Glenn's statement was "not factual and does not coincide with my recollections." (dpa)