Behind the release of the suspects is a religious counselling programme that uses Muslim clerics to rebut extremist views and instil moderate Islamic teachings. The theological programme, staffed on a volunteer basis by Singaporean Muslims, is part of a broader effort to rehabilitate JI members and enable their release. Clerics also reach out to families of detainees and the wider Muslim community to counter extremist propaganda.

Proponents say the success of Singapore's approach offers lessons to allies in the US-led war against Muslim extremism and an alternative to indefinite detention without trial of extremists in Guantanamo Bay and other prisons. In recent years, other countries in the Middle East and Southeast Asia have also promoted religious rehabilitation in jails bulging with terror suspects, with varying results.

Faced with swelling detention centres after a surge in troop deployments to trouble spots, US military commanders in Iraq have begun to take note. With an estimated 25,000 Iraqis in US custody, the US has in recent months introduced religious education programmes that are modelled, in part, on Singapore's scheme, and on a much larger programme in Saudi Arabia.

Marine Major-General Douglas Stone, who oversees US detention facilities in Iraq, told bloggers last month that religious courses at Camp Cropper had helped to 'bring some of the edge off' detainees who often had only a limited grasp of Islamic jurisprudence. General Stone, who spoke Arabic, said 'a few hundred' insurgents had been through the programme.

His goal was to release prisoners who were judged unlikely to return to insurgency activities, General Stone said. He said his approach was persuasive because 'it's how you win this war, not only the one in Iraq, but the one on a greater basis', according to a transcript of the interview provided by the Pentagon.

Rohan Gunaratna, a terrorism expert at Singapore's Nanyang Technological University and a consultant on the Singaporean programme, said an effective counter-terrorism strategy must combat religious indoctrination in society and, crucially, in jails. He said a 'war of ideas' could be won by releasing suspects into the Muslim community armed with Islamic teachings that debunked the do-or-die rhetoric of al-Qaeda and its offshoots.

'Deprogramming is not 100 per cent successful ... some will go back [to militancy]. But it's the only intelligent thing to do,' said Professor Gunaratna, author of Inside al-Qaeda. 'We've planted a seed ... Iraq was the beginning. I believe America can take this idea to Guantanamo, Afghanistan and other areas.'

Not everyone is convinced by this approach. Analysts said Yemen shelved a similar cleric-run programme in 2005 after former prisoners returned to extremism, usually by joining insurgent cells in Iraq. Of 400 militants freed after counselling, about half have since been put back behind bars. In contrast, only one Singaporean has been rearrested for allegedly contacting foreign militants.

Singapore's Deputy Prime Minister Ho Peng Kee told parliament earlier this year that the programme had worked well on some detainees, but not all, as it took time to turn around those who were deeply indoctrinated. 'We will continue to try to rehabilitate the others. But it is worth highlighting that a number are adamantly holding on to their radical and violent beliefs,' he said.

Mohammed bin Ali, one of the clerics working in the group secretariat, said that Singapore's Religious Rehabilitation Group had 21 volunteer clerics who led weekly one-on-one counselling sessions with detainees to 'correct their misinterpretations' of Islam . In the four-year-old scheme, counsellors systematically expose the distortions of JI doctrine, emphasising Muslims can live devoutly in multi-faith Singapore, where they make up about 15 per cent of its 4.2 million people. The government-funded group also hosts public forums and runs a website (rrg.sg).

'We believe in rehabilitation. No one is born a terrorist. No one wakes up one morning and says I'm going to be a terrorist. It's indoctrination ... and we're trying to bring them back to normalcy,' said Mr Mohammed, who had briefed US military officials in Iraq on Singapore's programme.

Counselling continues after suspects are released, while a parallel programme focuses on coaching the wives of detainees and ensuring they get financial support from the government. Mr Mohammed said moderate Muslims had a duty to counter extremist views in the community. 'The terrorist network [in Singapore] is crippled, but unless the ideology of extremism is countered, the threat will persist,' he said.

Malaysia and Indonesia have also sought to rehabilitate JI detainees using moderate Muslim teachings. In Indonesia, where JI bombed two Bali nightclubs in 2002, Nasir bin Abas, a disillusioned ex-JI cell leader, helped authorities to convince former colleagues to abandon their violent struggle for an Islamic state. In 2005 he published a book that exposed the group and its methods.

Other Indonesian militants have helped police behind the scenes in return for reduced jail terms and other privileges. In Singapore, a handful of detainees have played a similar role. But while Malaysia and Singapore have used colonial-era ISAs to detain terror suspects indefinitely, Indonesia has opted for public trials. Three of the Bali bombers are on death row, and more than 30 others were jailed.

Malaysia's prisoner release programme seemed to depend as much on coercion - the threat of harsher punishment for re-offenders - as theological re-education, said Zachary Abuza, a professor at Simmons College in Boston and an expert on JI.

'In Indonesia, unless you have a death or life sentence, there is light at the end of the tunnel without recanting. People enter into rehab programmes there because they want to,' said Dr Abuza.

In Saudi Arabia, authorities have created a religious counselling programme for about 2,000 prisoners accused of belonging to al-Qaeda. Some 700 had been released since 2004, of which 10 were later rearrested, said Christopher Boucek, a post-doctoral researcher at Princeton University, who is tracking the Saudi scheme.

Saudi Arabia uses family support networks to bring poorly educated al-Qaeda recruits into the programme and show how they have been tricked by corrupted Islamic teachings. Detainees who have participated in violent attacks are not eligible. As in Singapore, authorities have found that hundreds of other hardened militants refuse to join.

Despite the programme's success in forcing militants to recant, some Saudi government officials said public executions would send a tougher message to wrongdoers, said Dr Boucek. The counter argument, though, is that releasing detainees is a more effective rebuttal of militant propaganda. 'The state is fighting a war of ideas ... as part of this process, what they're doing with these guys is showing that if you co-operate with the state, bad things don't happen,' he said.

Applying the lessons of Singapore and Saudi Arabia to counter-insurgency in Iraq could be a stretch, according to terrorist experts with experience there.

Unlike in prisons where terrorist suspects are held separately, US military officials have warehoused thousands of insurgents in giant holding pens that extremists reportedly use as recruiting centres. Edward O'Connell, a senior analyst at Rand Corp who is studying Iraqi detainee motivations for the Pentagon, said the US now faced the uphill task of trying to weed out religious and sectarian insurgents from hired gunmen and criminals.

He warned that religious education in camps could backfire, and General Stone's belief in theological debate to rebut extremism, while laudable, was untested in the maelstrom of a violent insurgency. 'You've got to be careful with re-education and rehabilitation,' said Mr O'Connell. 'You don't want to enhance the union of religion and criminality and nationalism in a troubled state.'