Rumours a captured pro-Indonesian militiaman was summarily executed by Australian troops in East Timor had floated around special forces circles for some time, a defence commentator said today.

John Farrell, author of the recently published book on the Special Air Service – Specwarops – said there were many claims about purported excesses of the SASR and they needed to be treated with suspicion.

"Rumours about the fate of a militiaman have run riot over the past three years," he said. "I have heard scuttlebutt relating to an extra-judicial execution. I have also heard rumours that no execution took place and the militiaman was simply given the boot."

The incident, now being investigated by the army, allegedly occurred on October 6, 1999 as Australian troops, supported by the SASR, occupied the town of Suai in the western border region. They captured a large group of militia.

SASR troops were returning from escorting the convoy of captured militia when they were ambushed by other militia, believed to be from the Laksaur group. In a sharp firefight two SASR were wounded with two militia shot dead and nine captured.

The rumours about summary executions relate to a senior SASR soldier, angered at the injuries inflicted on his soldiers, either beating or using his pistol to shoot dead one or more of the captives back in Suai.

Mr Farrell said there many rumours flew about the SASR and he tended to take them all with a grain of salt. He said Australians should be aware that the SASR was not the Red Cross.

"They are super-conditioned special action forces. They are the last resort and the final solution. Expecting them to do anything other than lean on the bad guys with extreme efficiency is simply naive," he said.

But he said there was no justification for executing prisoners. "It is bad for a soldier's soul but it is also very bad for the overall war effort," he said.

"You want your enemy to think when they surrender to a western force that they are heading to a reasonable camp. You don't want them to think they are going to be shot dead, or they don't surrender. "It's not a good look, especially when there is no vital information to be got out of the others who are watching. It is just beyond excuse."