Australian Prime Minister John Howard has been asked to give evidence to a commission investigating claims that the country's wheat exporter bribed Saddam Hussein. The announcement comes as two senior ministers are preparing to testify before the commission, which is investigating claims that an Australian enterprise illegally paid $220 million to the former Iraqi president under the United Nations' oil-for-food program.

The Australian government has strongly denied it knew that the country's monopoly wheat exporter, A.W.B. Limited, was paying bribes to Saddam Hussein.

Two senior ministers are preparing this week to face the official inquiry set up to investigate the allegations.

Trade Minister Mark Vaile is to testify, followed by Alexander Downer, Australia's long-serving foreign minister. Both men are expected to answer allegations that they ignored warnings from diplomats in Iraq that A.W.B. was involved in corruption.

Mr. Downer has described as "preposterous" claims that the government was involved in a conspiracy to flout sanctions against Saddam Hussein. Opposition politicians have insisted that the government must have known about the bribes but did nothing.

Prime Minister John Howard has been asked to submit a statement to the inquiry and may also have to appear in person later this week.

Mr. Howard says he has nothing to hide.

"I've said all along that this is an utterly transparent process which is not protecting the government but which is designed to get to the truth of this matter and I am more than happy to comply with the request made by the commission," he said.

A.W.B. was the largest single supplier of humanitarian goods under the United Nations oil-for-food program, which began in Iraq in 1996.

A U.N. report last year said the Australian wheat exporter paid $220 million in kickbacks to secure lucrative Iraqi grain contracts. That prompted the Australian government to establish the inquiry commission.

A.W.B executives have testified before the commission in Sydney but they denied any wrongdoing and say they were deceived by dishonest officials in Baghdad.

The commission, headed by retired judge Terence Cole, began hearing evidence in January. The inquiry is to determine if A.W.B. managers broke any Australian laws in their dealings in Iraq.