Australia is to review the cases of a group of 30 asylum seekers after some of them converted to Christianity.
By Phil Mercer
BBC News, Sydney
The migrants, from Iran and Iraq, are being held in detention centres after their original applications for refugee status were rejected.
Immigration officials said their conversion to Christianity, and changed conditions in their home countries, meant their cases would be reassessed.
It was unclear how many of the 30 have renounced Islam for Christianity.
Immigration officials have said that in some cases, new information had been obtained about the dangers they could face if they were deported.
Australia's Prime Minister, John Howard, said there were concerns that if detainees were sent back to their homelands they could suffer persecution because they had embraced a different religion.
Mr Howard has stressed that this policy of review was not biased in favour of Christians.
The main opposition Labor party, however, has warned that reviewing asylum claims based on religion would damage the country's reputation.
It said other detainees could be encouraged to adopt Christianity simply to stay in Australia.
The Sydney Morning Herald newspaper said the move was a "face-saving way" for the government to soften its policy on failed asylum seekers who have been in custody for more than three years and cannot be repatriated to their countries of origin.
Australia's policy of automatically detaining all asylum seekers while their claims are investigated has drawn international criticism.
Ministers have justified these measures on the grounds of national security and health.