Convicted terror supporter David Hicks was released from an Australian prison Saturday after completing a six-year, U.S.-imposed sentence for aiding terrorists.

Hicks was the first person convicted at a U.S. war-crimes trial since World War II after he pleaded guilty in March to providing material support to Al Qaeda.

The former Outback cowboy had been fighting with the Taliban in Afghanistan when he was captured in December 2001 by U.S.-backed forces. A month later, he was sent to the U.S. naval base in Guantanamo Bay, Cuba, where he spent more than five years without trial.

A U.S. military tribunal sentenced Hicks — a Muslim convert who has since renounced the faith — to seven years in prison, with all but nine months being suspended, after he confessed to aiding Al Qaeda during the U.S.-led invasion of Afghanistan after the terrorist attacks of Sept. 11, 2001.

Under a plea bargain, Hicks was allowed to serve the remainder of his sentence at a maximum security prison in his hometown of Adelaide in South Australia state.

Under the deal, Hicks has forfeited any right to appeal his conviction and to a gag order that prevents him speaking with news media for a year from his sentencing date. The government concedes the gag order may not be enforcable in Australia, where Hicks has not been convicted of any crime.

Hicks, who has been described as depressed and anxious by family members, was not expected to speak to the media upon his release. But his father, Terry, said Hicks would issue a brief statement through his lawyer, David McLeod.

"There'll be some sort of apology," Terry Hicks told Sky News television. "It is important to him that he gets this message across and thanks everybody who has been supportive of him."

Hicks' lawyers have described their client as an immature adventurer who traveled to Afghanistan only after his application to enlist in the Australian army was rejected because of his lack of education.

The Hicks case became a cause for rights campaigners in Australia, and a political problem for former Prime Minister John Howard, who was criticized for allowing an Australian citizen to spend so long behind bars in Guantanamo.

Prime Minister Kevin Rudd, who defeated Howard at elections in November, was a strong critic of Hicks' treatment and the military tribunal system that convicted him, saying it could not deliver justice.

But Rudd has not challenged the plea deal, and said Friday that Hicks would have to comply with restrictions placed on him by a court at the request of Australian federal police.

"Mr. Hicks should be treated no differently to any other Australian citizen in these circumstances and our expectations of Mr. Hicks is that he would comply with the requirements which have been imposed upon him," Rudd told reporters in the southern city of Melbourne.

A federal court ruled last week that Hicks was a security risk because of the training he had received in terrorist camps in Afghanistan. The court was told he met Al Qaeda leader Usama bin Laden at least 20 times.

Under the court order, Hicks must report to police three times a week and obey a curfew by staying indoors at locations decided by police. Other restrictions include that he not leave Australia or contact a list of terror suspects.

The restrictions will last for one year. Hicks will have an opportunity to challenge the orders at a hearing set for Feb. 18, though his lawyers say they doubt he will do so.

Terry Hicks said his son was eager to resume a normal life in Australia, and hoped to find a job and attend university.