Wellington  - New Zealand Foreign Minister Winston Peters was reportedly facing the sack Friday after the Serious Fraud Office announced an investigation into donations by wealthy entrepreneurs to his political party.

Prime Minister Helen Clark said she would talk to Peters during the day to discuss allegations that the donations "did not reach their intended destination" and involved "serious and complex fraud."

A defiant Peters told Radio New Zealand, "I will talk to the prime minister about this matter later today with the concrete evidence that she will know these allegations are vile, malevolent, malicious and wrong."

He accused the media of setting up a "kangaroo court of public opinion" to vilify him and his nationalist New Zealand First party ahead of a general election due by mid-November.

Clark told reporters Thursday that Peters should be presumed innocent until proven guilty, but conceded that she had made a practice of standing down ministers facing serious charges during investigations.

Newspapers said it was inevitable that Clark would suspend Peters if he refused to stand down voluntarily.

"The serious nature of the probe makes it impossible for him to hold a government role as crucial as minister of foreign affairs," the New Zealand Herald said.

Serious Fraud Office director Grant Liddell said Thursday the inquiry would centre on donations made to the New Zealand First party by millionaire property developer Sir Robert Jones and the Vela family of companies, adding, "I have sufficient information that gives me reason to suspect that an investigation may reveal serious and complex fraud."

Liddell said it was entirely possible that there were "innocent and honest explanations." But added, "The allegations concern important matters relating to the funding of a political party, which go to the heart of the democratic process, and involve a minister in the government."

Peters dubbed the statement "ridiculous in the extreme," adding, "We will meet this investigation head-on."

He said fraud investigators had not talked to him and he could convince them of his innocence "in five minutes."

Liddell said his agency's investigation would not include a 100,000-New Zealand-dollar (70,000-US-dollar) donation to Peters from expatriate New Zealand billionaire Owen Glenn that is the subject of a separate continuing investigation by Parliament's privileges committee because it was clear it was donated for the minister's legal expenses.

The Glenn donation has stirred a major political row and Clark cast herself into the centre of it Thursday when she revealed for the first time that Glenn told her about it 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 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 parliamentary convention, she told reporters.

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

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

John Key, leader of the main opposition conservative National Party which is well ahead in opinion polls to win the coming election, has said that he would not have Peters in his government if he had to form a coalition unless he could come up with a "credible explanation," which he thought was unlikely.

Peters, 63, is a veteran political maverick who has served in governments on both sides of the spectrum, being deputy prime minister and treasurer under a National Party administration in the 1990s. (dpa)