The Sydney Olympics, held in September of 2000, were considered a resounding success on the world stage but behind the scenes, cabinet documents from the Howard government released Friday, show officials were worried about the possibility of violent public attacks.

The war on terror had not yet been waged by the United States and its allies in the wake of the September 11 attacks but the threat of terrorism was something cabinet's National Security Committee was giving great consideration to.

Former deputy prime minister at the time John Anderson said at the release of the documents surveillance efforts were "quite deep" during the lead-up to the event.

"The surveillance, I have to tell you, was quite deep at the time as we tried to identify those who might want to make trouble building largely on what had been learned out of Atlanta," Mr Anderson said.

"Nonetheless, [the efforts] went very well."

Australia's domestic spy agency, ASIO, told the committee the greatest harm to the Games would come from a terrorist incident as had happened in the 1996 Olympic Games in Atlanta. The agency added United States, Israel and Turkey were most at risk.

To prepare for the threat, three simulated exercises were conducted during 1999 and 2000 to test how Australia's security and intelligence agencies would fare.

The first two, held in mid and late-1999, involved an aviation hijacking and a maritime siege on Sydney Harbour.

The final one, Ring True, was held over two days in May 2000 in Sydney's Homebush and Canberra's Bruce Stadium. Sydney's mock incident involved a chemical attack and required cooperation between state and Commonwealth authorities while the hostage operation in Canberra was handled by the Australian Federal Police.

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After all three operations had been undertaken, the final verdict suggested security agencies were "well-placed" to handle any incidents but noted there were communication and jurisdictional problems between state and federal teams. New South Wales Police, for example, were unable to successfully confirm the nationalities of hostages.

Ultimately, that assessment was never tested and the games went ahead without any violent attacks.

Foreign countries concerned over security requested bringing and carrying their own firearms into Australia in order to protect their entourages, cabinet minutes also show.

In one example, the United States requested a weapons exemption for personnel tasked with protecting the US president's daughter, Chelsea Clinton, along with other dignitaries.

Cabinet denied the requests, worrying an exemption for one country would result in pressure from other nations wanting the same.

"It was a very difficult debate around the table," Mr Anderson said, reflecting on discussions between the allies over the request.

"I can only say that it was met with benign silence but I suspect that [the decision to reject the United States' exemption request] was resented."