Canberra Catholic Archbishop Christopher Prowse.

Canberra Catholic Archbishop Christopher Prowse. Photo: Katherine Griffiths

Australia's treatment of asylum seekers is inhumane and lacks compassion, Canberra's Christian leaders say.

Newly appointed Catholic Archbishop of Canberra and Goulburn Christopher Prowse (pictured) spoke out about public attitudes towards asylum seekers at a church service at St Christopher's Cathedral in Manuka on Wednesday night.

Archbishop Prowse said he felt ''sick in the stomach'' when he heard an asylum seeker, later revealed to be 23-year-old Iranian man Reza Barati, had been killed on Manus Island.

He said he was concerned about the lack of humanity in the public portrayal of asylum seeker arrivals.

''At least in the past we saw people on boats coming to Australia, even if they weren't able to stay here. Now, we only hear reports, no photography, we don't even see human faces of people struggling.''

Archbishop Prowse said he wondered what was happening at the Manus Island detention centre that caused such a great deal of desperation and hopelessness among asylum seekers. He said the Australian government had an important duty to protect the country's borders, but that needed to be balanced against its international responsibilities to those seeking refuge.

''I'm just waving an ethical and moral reservation about how it's all going,'' he said.

Anglican vicar general for Canberra and Goulburn Trevor Edwards said compared with the numbers of asylum seekers arriving in other countries, boat arrivals in Australia were relatively few.

He called on church-goers who disapproved of the treatment of asylum seekers to make their views known to the government.

''I think it diminishes us as a nation to demonise people who are made in the image of God and just seeking help.''

Bishop Edwards said Canberra church leaders had condemned the asylum seeker policies of both major parties as unjust and inhumane before last year's federal election and he stood by that assessment.