A 51-year-old man who has lived in Western Australia since he was one year old is stuck in limbo on Christmas Island and facing possible deportation to the UK.

He is one of hundreds of people who have lived the majority of their lives in Australia but because they have served more than 12 months in jail have been caught up in changes to the Migration Act that lawyers say are tearing families apart.

Ian Wightman was last year convicted on charges of starting a scrub fire and served 15 months in jail.

He was released in September but immediately apprehended and detained at a WA detention centre for eight weeks before being flown to Christmas Island, allegedly without warning, at 3:00am last Wednesday.

Speaking from Christmas Island, Mr Wightman described the detention as "mind-numbingly degrading".

"It's an open-ended sentence and there's no information, you can't get any information," he said.

"There's a constant struggle every day to keep your sanity, try to maintain who you are without falling into the depths of bloody despair."

Do you know more about this story? Email 7.30syd@your.abc.net.au

Under recent changes to the Migration Act, any foreigners who serve a prison sentence greater than 12 months automatically have their visas revoked.

Immigration Minister Peter Dutton was unavailable to comment but has previously said he made no apologies for the tough approach because it targeted people who were detracting from Australian society, not adding to it.

Mr Wightman described his detention as a "kick in the guts" and said most of the other detainees on Christmas Island were not serious criminals.

"Very, very few people that are in detention here are because they're arch criminals or they're meth-dealing bikie killers," he said.

"You've got people in here for traffic offences, people that are in here that had a run-in with the law 21-and-a-half years ago."

Ian Wightman always considered himself Australian despite never applying for citizenship. ( Supplied )

Mr Wightman's brother Gary said his family was in disbelief.

"Ian was convicted of a crime and sentenced and punished," he said.

"He's served his time, he did his rehabilitation, he did the courses required, he attended the counselling, he was viewed for parole and approved and he was released a free man, upon which he was arrested."

He said Ian always considered himself Australian despite never having applied for citizenship.

"I can't see Ian as anything other than Australian. Unfortunately, Ian probably viewed exactly the same, otherwise he would have done something about the paperwork."

Families being 'torn apart', appeal options limited

It follows dozens of similar cases involving New Zealanders that sparked diplomatic tensions between the trans-Tasman neighbours last month.

Previously, those with serious criminal records were targeted for deportation, but under the new legislation anyone with a sentence of greater than 12 months is captured in the net and that 12 months can also be made up of cumulative sentences.

Since the legislation changed last December, about 780 non-citizens have had their visas cancelled compared to 372 revocations in the three years between July 2011 and July 2014 — 151 of those have been deported.

Migration lawyer Alisdair Putt said the changes were tearing families apart.

"Many people have been here decades, they've often got Australian children, longstanding Australian partners, family links, and often have no connection with overseas countries and in some cases they may not even speak the language," he said.

He was also concerned that the Immigration Minister was deciding many matters personally, causing lengthy delays with limited appeal options.

"If the Minister makes a decision personally, there is no merits review to the Administrative Appeals Tribunal," he said.

"So, as a result, if you've been here 40 or 50 years and the Minister decides personally that you are to be deported forever and potentially separated from family and children, you have no rights to merits review."