The Australian government has asked for new assurances from Iran that trade is not being disrupted, despite promises by Tehran that there were no restrictions, the Trade Minister's office said on Monday.
Australia's main export to Iran, wheat, has already stopped in 2004 because of a big crop in the Middle Eastern country.
Interruptions to other exports, which include coal, wool and machinery, have also been occurring. Anecdotal evidence was that trade was still being disrupted, Trade Minister Mark Vaile's spokesman, Matthew Domain, said on Monday.
"We are still seeking urgent clarification from the Iranian government that Australia's trade with Iran won't be compromised in any way," he said.
No reason had been given for disruptions but the Tehran government was known to be concerned about Australia's opposition to Iran's nuclear programme and its support for International Atomic Energy Agency investigations into Iran, Domain said.
"We absolutely reject a link between international security and bilateral trade issues," he said.
Whether Australia's participation in the military invasion and occupation of neighbouring Iraq was involved was a matter of speculation, he said.
Latest concerns follow recent diplomatic questions on the issue and a letter from Vaile to the Iranian commerce minister. This produced advice from Iranian Foreign Affairs that there were no restrictions on trade with Australia.
A warning on the federal government's Trade Commission Austral Web site (www.austrade.gov.au) about recent rejection of exports by Iranian authorities still stood, an Austral spokesman said on Monday.
"Rejections have occurred across product types and may continue," said the warning, which also said that there had also been reports of unexpected difficulties with letters of credit.
Australia exported goods to Iran worth A$614 million ($429 million) in calendar 2002, while importing A$37 million worth of merchandise.
A spokesman for wheat exporter AWB Ltd told Reuters that Australia expected to export no wheat to Iran this year because of a large domestic crop in the Middle Eastern country.