Relations between Australia and Iran, traditionally one of the minor tangents of international diplomacy, have leaped onto a new level with allegations that the Iranian ambassador is Canberra's leading diplomatic swinger.

It all started when the ambassador, Ali-Reza Heravi advertised for a hostess to live in at his spacious embassy on Mugga Way, the dress circle of Canberra's embassy row.

The ad stipulated an "attractive girl aged 19-26."

Heravi said that in fact he was looking for two hostess to live at the embassy residence and that he would pay each of them between $200 and $300 a month plus all expenses, including food, drinks, free telephone and the use of two horses.

He denied emphatically allegations by some women he interviewed for the job that he had made improper suggestions to them.

But two of the women have signed statutory declarations which were published in a Sydney newspaper claiming the ambassador told them that sex was part of the job, they would be required to sleep with him on alternate nights.

The paper identified the women only as Ann and Barbara. Ann claimed that during the interview on the embassy couch "he put his hand on my thigh and told me not to be upset or jealous if he slept with Barbara as well."

Barbara claimed that during her interview, "He told me about the job and then he grabbed me and kissed me. He also tried to put his hand down my dress. I was shocked. He said he liked me. He said I would have to share the bed with him one night and then Ann would be with him the next night."

Canberra is a normally staid, some would say sleepy town of 200,000 people. It was plonked in the middle of a sheep station well away from Australia's main population centers 50 years ago because the two big cities - Melbourne and Sydney - could not agree that the other should be the capital.

Mugga Way is the city's Massachusetts Avenue - with a differebce. The broad street is lined with huge and very Australian eucalyptus trees. But the spreading mansions where the diplomats live are universally fenced by hawthorn hedges, reflecting Australia's inability to shake off its attachment to things English.

The city's stolid morning paper, the Canberra Times, indulged itself in headlines about the ambassador normally reserved for declarations of war or the occassion 15 months ago when the nation's governor general sacked the Socialist government of former Prime Minister Gough Whitlam.

It was the first hint of scandal at Canberra's Iranian embassy, or any other embassy in the quiet down-under capital if the truth be known.

And there was the handsome, forthyish Heravi, pleading with Aussies to believe him. He had "not raped, not violated, not approached" the women or suggested that bedding down with him was part of the duties of a well-behaved embassy hostess.

"I cannot imagine why they should say this. They can only say such a thing because they want publicity or they want money. And I would not give them money."

Herave, who is divorced, said he was upset by the allegations and was now "bitter= about Australia after having devoted 14 months of his life to building good diplomatic relations between Australia and Iran.

The relations, as it happens, are currently a bit vague - at least they were before the allegations. The shah visited Australia three years ago and then-Prime Minister Whitlam was keen to develop close relations with Iran, along with virtually every other country in the world Australians had formerly heard little of.

There was talk at the time of Iran and Australia taking on the task of being the military protectors of peace in the Indian Ocean.

But nothing much came of it, and the current prime minister, conservative Malcolm Fraser, is much more keen for the U.S. Navy to do the job.

What will happen to the countries' bilateral relations in the future is a little uncertain now.

Ambassador Heravi said that while he did not expect to be recalled by the shah over the hostesses incident, he would have no regrets about going home after all the publicity.

In the meantime, he is still looking for two hostesses.

But this time, he is defining the qualities exactly.

"An impeccable background, grace and personality" were essential.

An embassy spokesman also suggested that nursing experience would be useful. The Iranian ambassador has a bad back and severe trouble with corns in his feet.