He said an Iranian Revolutionary Guard gunboat moved close by and its armed personnel made "very overt gestures". The boarding party commander ordered the Australians to re-board the cargo ship.

"He got his boarding party back on to the ship and established a very credible and appropriate defensive position," Commodore Gilmore told reporters in Canberra. "(They) began what I think is very unique in the Australian way and that's the capacity to negotiate, to introduce extra weighpoints if you like, in the continuum of force," he said. 'Tense period'

Another four Iranian military boats carrying rocket-propelled grenade launchers arrived to reinforce their colleagues in the next 45 minutes, Commodore Gilmore said. "Over a tense period of four hours the boarding party was eventually successfully extracted by helicopter back to the (HMAS) Adelaide.

The Australians had originally boarded the MV Sham from two inflatable boats launched from the HMAS Adelaide while a Seahawk helicopter carried out surveillance. No shots were fired during the encounter. "We were able to keep that as the case by the very deliberate, well-considered and well-executed negotiation process that the Australian boarding officer undertook.

"The determined approach, the no-nonsense approach of the Australian boarding party, was able to effectively manage that situation." The Australians' handling of the stand-off was today being compared to that of British sailors captured by Iranian forces in March this year during a similar operation and accused of straying into Iranian waters.

The Britons were paraded on Iranian television and eventually released amid a diplomatic storm. Commodore Gilmore said there were similarities and differences between the two incidents. "It's very difficult to predict the (British) outcome should have been the same as the Australian outcome because it wasn't the same circumstances."

Commodore Gilmore said the intentions of the Iranians had not been clear.

"It was certainly quite overt and they were attempting to establish what the Australians were doing, there's no doubt about that." Colourful language

A BBC reporter, quoting sources, said the Australian sailors used colourful language to help hold off the Iranians. Commodore Gilmore said: "As Australians I think we all know our capacity to engage, to defuse by discussion and they indeed did that. "We might imagine what (language) was there - I haven't delved into that.

"The important thing to note is that it worked." The commodore, who commanded the joint task maritime task force in the Gulf shortly after the incident, said the Australian sailors had handled themselves superbly.

"Those values that I think were displayed really do highlight what is unique about the Australian soldier - the courage that was shown in demanding circumstance, the loyalty, the teamwork were there throughout." Two members of the team were awarded the Distinguished Service Medal for their conduct during the incident.

Commodore Gilmore said it was not reported at the time because while unique in some ways it was representative of operations in the Gulf at the time. "From an operation circumstance I don't believe there was any recognition there was a need to highlight that particular activity." AAP, with staff reporter