The Australian Nationals leader, Mark Vaile, has rejected allegations that Foreign Minister Alexander Downer knew about the AWB scandal before it was revealed.
Former Austrade director John Finnin, who was Australia's top Middle East trade official, told Fairfax newspapers that Mr Downer would have known AWB, Australia's single-desk wheat exporter, was paying kickbacks to Saddam Hussein.
Mr Finnin says he met with the owners of Jordanian trucking firm Alia in September 2003.
Alia was was used to channel funds to Saddam through "trucking fees".
"I was the senior trade officer in the region and Iraq was my responsibility.
The foreign minister had enough advisers to know that (the meeting occurred)."
Mr Vaile, a former trade minister, retorted:
"We established, for all intents and purposes, a Royal Commission that was overseen by Royal Commissioner Cole into this whole issue.
It's conclusion was that there was certainly no wrong-doing by government or by government officials and that is a matter on the public record.
As far as we are concerned, the case is closed - it's finished."