It is believed the missions have involved gathering intelligence on terrorism and scoping rescue strategies for Australian civilians trapped by kidnapping or civil war. But the operations have raised serious concerns within the Australian military and intelligence community because they involve countries where Australia is not at war. There are also concerns within the SAS that the troopers do not have adequate legal protection or contingency plans if they are captured. ''They have all the espionage skills but without [ASIS's] legal cover,'' said one government source. In a comment relayed to government officials, one soldier said: ''What happens if we get caught?'' Australian National University professor Hugh White, a former deputy secretary of Defence, said: ''Such an operation deprives the soldier of a whole lot of protections, including their legal status and, in a sense, their identity as a soldier. I think governments should think extremely carefully before they ask soldiers to do that.''

Despite the dangers, then foreign minister Kevin Rudd last year asked for troopers from 4 Squadron to be used in Libya during that country's conflict. His plan was thwarted by opposition from Defence Minister Stephen Smith and chief of the Defence Force General David Hurley. Both Mr Smith and General Hurley declined to be interviewed about this story. SAS 4 Squadron is based at Swan Island, near Queenscliff, a high-security defence facility that has doubled in size over the past decade, in part to accommodate the new squadron. The squadron was formally raised in 2005 by the Howard government, but The Age has learnt that its new intelligence-focused role was authorised in late 2010 or early last year by Mr Smith. The SAS is also at the forefront of gender reform in the Australian military, with six female soldiers being trained in the United States for their work with 4 Squadron.

Collecting intelligence overseas without using violence is the main function of ASIS, which was created in 1952 but not officially acknowledged until 1977. Since the mid-1980s, ASIS officers have been refused permission to carry weapons or use violence, but in 2004 the Howard government amended legislation to allow them to have weapons for self-defence and to participate in violent operations provided the officers themselves do not use force. It was around that time that the creation of the fourth SAS squadron was authorised, with its soldiers expected to be an elite version of bodyguards and scouts for ASIS intelligence officers. The African operations by 4 Squadron initially centred on possible rescue scenarios for endangered Australian citizens, such as freelance journalist Nigel Brennan, who was held by Somali rebels. The soldiers have also assessed African border controls, explored landing sites for possible military interventions and developed scenarios for evacuating Australians, as well as assessing local politics. ASIS officers are legally permitted to carry false Australian passports and, if arrested, can deny who they are employed by. ADF members on normal operations cannot carry false identification and cannot deny which government they work for.

While the SAS has worked alongside Australia's intelligence agencies for decades, the creation of a dedicated squadron mirrors the US model, where the military and the intelligence services have closer links. That relationship has resulted in the growing importance of the US Joint Special Operations Command, whose soldiers killed al-Qaeda leader Osama bin Laden in Pakistan last year. Some staff within the ADF's special operations command see 4 Squadron detracting from what they believe is the main effort - the war in Afghanistan and the counterterrorism teams on the east and west coasts of Australia, manned by soldiers from the 2nd Commando Regiment and the SAS respectively. But others argue it is vital to Australia's contribution to the American fight against al-Qaeda - particularly in the Horn of Africa. US intelligence believes many second-tier al-Qaeda fighters and leaders from the Afghanistan and Pakistan region have fled there. The intelligence gathered by the Australian soldiers in countries such as Kenya all flows into databases used by the US and its allies in Africa. Loading

Australia's security service ASIO is also increasingly concerned by the domestic threat posed by Somalia-based terror group al-Shabaab. ASIO holds concerns that a small group within Australia's growing Somali community is sending money to al-Shabaab. Follow the National Times on Twitter: @NationalTimesAU