Baghdad: The spiritual leader of Iraq's Catholics, elevated to the rank of cardinal last month, called on US forces to free Saddam Hussain's ailing former deputy prime minister Tariq Aziz if there was no evidence against him.

Aziz is a Chaldean Christian, Iraq's biggest Christian group, and his presence in Saddam's government was often held up as evidence of the former Iraqi leader's religious tolerance.

In an interview, Emman-uel III Delly, the Chaldean patriarch of Baghdad, also called for religious freedom in Iraq, where many Christians have been kidnapped, killed or forced to flee.

"We have no freedom of religion in Iraq but hopefully that will become the case one day because the Lord created us free and everyone should have freedom of religion," he said.

Aziz is now in US custody and is reported to be in poor health, suffering from diabetes. He is being held without charge and his family has repeatedly called for his release.

"In terms of Tariq Aziz, who has worked so long for Iraq and I am sure still wants good things for Iraq, we have to demand the release of all those who were captured and which have no evidence against them ... as soon as possible," Delly said.

Delly, a critic of the US-led invasion in 2003, said he had tried to visit Aziz, but his request had been turned down.