The Prime Minister is being urged to reopen the Christmas Island detention centre to detain terrorists, after raising the possibility of indefinite detention of radicalised Australians with the right to citizenship overseas.

But the indefinite detention of terrorists and terrorist sympathisers could pose new security challenges for immigration detention in Australia, with other MPs warning Australia must avoid the experience of Northern Ireland.

Prime Minister Scott Morrison has already flagged that the government will pursue law changes to allow it to deport terrorists who do not hold dual citizenship but could be eligible to claim it if they applied.

Asked why any foreign country would accept the terrorists, Mr Morrison said if they did not Australia could detain the terrorists here.

“If we have a reasonable view that someone has citizenship – it may be by descent or they may have been born somewhere else – then we will be able to strip them of their Australian citizenship, and we’ll be able to have them deported back to the country from which they do have a citizenship,” he told Seven’s Sunrise on Friday.

“If they’re in a position not to be deported, they’ll remain in immigration detention.

“The point is, we’re not going to cop people who act contrary to what their citizenship has granted them and that is the freedom and the liberties that goes with that responsibility.

“Their citizenship should go if you commit a terrorist act in Australia,” he said.

The British Army had a policy of internment in Northern Ireland during “the troubles” from 1971 until December 1975. Nearly 2000 people were detained during that time, but the European Court of Human Rights. later described the interrogation tactics used as “torture”.

Australia’s detention centres already deal with large numbers of criminals as a result of the shift to detain asylum seekers who arrive by boat offshore. 

Their ranks include significant numbers of New Zealand bikies and criminals who are held in detention before being deported on character grounds. 

On Friday, Liberal MP Jason Wood urged the PM to go further, admitting he was open to the idea of reopening the Christmas Island detention centre.

“Round them all up in jail and send them to Christmas Island, I don’t care where they put them. Then the young ones in jail for stealing a car don’t get recruited,” he told The New Daily exclusively.

“Number one, you want them to keep away from mainstream prisons. Then they become pretty much the dominant factions in prison.”

However, Mr Wood said what is urgently needed is domestic violence-style apprehended violence orders. They would allow police to step in early and stop young people from associating with radicals.

Mr Wood said he had been approached by parents who had said “we need your help, my son is being radicalised and the police can’t do anything”.

The former police officer said the 2014 death of 18-year-old Victorian Numan Haider, who was shot after he stabbed a police officer, was a reminder police never know when a terrorist sympathiser would “go off”.

“He was going down to Dandenong Plaza with an ISIS flag,” he said.

“There are 400 Numan Haiders out there and, given the right conditions, some of them will go off.” 

Another Liberal MP, who declined to be named, backed the Christmas Island option.

“We could put them on Christmas Island. Bang them on Christmas Island. No reason why we couldn’t open it up again,” he said. 

“Time and time again we’ve identified people with the potential for terrorist action. They get bailed and they go out and kill people.”

“Detention may have a bad smell to it but it’s better than people being killed in Bourke Street.”