A growing number of Australian churches have declared they will provide sanctuary for asylum seekers in the wake of Wednesday's High Court decision dismissing a challenge to the Federal Government's offshore detention program.

The decision has allowed for the deportation of 267 asylum seekers from Australia to Nauru, including 37 babies born in Australia.

"It's basically a very strong act of civil disobedience on the part of the church and derived from the very ancient power of the church to give sanctuary and basically give people protection from authority...There are a range of different ways and means which churches in various countries have exercised this right or this power..."

- Misha Coleman, executive officer of the Australian Churches' Refugee Taskforce

The Anglican St John's Cathedral in Brisbane was the first church to be declared a sanctuary. Rev Dr Peter Catt, the dean of Brisbane, made the declaration following the decision on Wednesday.

Rev Dr Catt said there was "irrefutable evidence from health and legal experts that the circumstances asylum seekers, especially children, would face if sent back to Nauru are tantamount to state-sanctioned abuse".

Since then at least 14 further churches around the country have done so and Misha Coleman, executive officer of the Australian Churches' Refugee Taskforce, said the number is growing.

Along with St John's Cathedral in Brisbane, other churches which have declared sanctuary include Anglican churches such as St George's Cathedral in Perth, St David's Cathedral in Hobart, St Matthew's Church in Albury, the Church of the Resurrection in Brisbane, St Cuthbert's Church in Darlington, Western Australia, Gosford Anglican Church, and Paddington Anglican Church in Sydney.

Churches from other denominations include the Wesley Uniting Church in Perth, Pilgrim Uniting Church in Adelaide, St John's Uniting Church in Essendon, Melbourne, Pitt Street Uniting Church in Sydney, the Wayside Chapel in Sydney and the GraceTree Baptist Church in Coburg, Melbourne.

Ms Coleman says the concept of sanctuary dates back to the Old Testament in the Bible and was used in the Middle Ages to allow people to seek sanctuary from arrest in churches.

"More recently you may know that more than 200 churches in Germany this year have taken in asylum seekers who were under threat of deportation..." she says.

Ms Coleman said that while churches have long been a haven for women and children seeking shelter from situations of domestic violence in Australia, the concept of the use of sanctuary for the purposes of sheltering asylum seekers was "untested" in Australia's court.

"It's basically a very strong act of civil disobedience on the part of the church and derived from the very ancient power of the church to give sanctuary and basically give people protection from authority..." she said. "There are a range of different ways and means which churches in various countries have exercised this right or this power..."

Ms Coleman said those who were offering sanctuary were aware of what it could mean. "There's a section in the Migration Act which has a 10 year jail sentence for anybody who harbours what they call a 'non-citizen'; there are also provisions in the criminal code that if you block a federal government officer, there are hefty jail terms associated with that as well."

She said churches who had expressed interest had been advised to seek legal advice about taking such a course of action.

Ms Coleman would not disclose whether any asylum seekers had sought sanctuary in any churches as of 4pm on Thursday.

In answer to critics who suggest that the move is no more than a stunt to get publicity, Ms Coleman responded: "We have priests and vicars who are exposing themselves to 10 year jail sentences and everything that goes along with that. If that's not serious, I don't know what is."

She said the move was indicative of the "exasperation" that church communities over the Federal Government's "complete failure of any sort of moral leadership" on the issue.

Immigration Minister Peter Dutton told Sky News on Thursday that the Federal Government won't be dragging asylum seekers out of churches to take them back to Nauru.

He said the bulk of those asylum seekers involved were people accompanying ill family members and their cases would be decided on individual medical advice.

Mr Dutton has repeatedly said his intention was not to put any child in harm's way and that while the government took a compassionate approach, it also had to be realistic about the threat posed by people smugglers.