Prime Minister Scott Morrison has weighed in on the case of a convicted child sex offender, saying the Federal Government will "punt" him.

Key points: Mohammad Hassan Al Bayati was sentenced to at least two and a half years jail for the sexual assault of a 3-year-old girl in December 2016

Mohammad Hassan Al Bayati was sentenced to at least two and a half years jail for the sexual assault of a 3-year-old girl in December 2016 He came to Australia from Iraq by boat in 2011 and was granted a permanent residency visa

He came to Australia from Iraq by boat in 2011 and was granted a permanent residency visa Prime Minister Scott Morrison says he will be kicked out of the country

On Tuesday, 30-year-old Iraqi-born Mohammad Hassan Al Bayati was sentenced for the sexual assault of a three-year-old girl in December 2016.

He was working as a security guard at the Homebush DFO shopping centre in western Sydney, when he took the girl away from the centre's playground while her mother was Christmas shopping.

Security camera vision shows Al Bayati taking the girl into an area without surveillance, where he assaulted her.

The New South Wales District Court sent Al Bayati to jail for four-and-a-half years' jail, with a non-parole period of two-and-a-half years.

He came to Australia by boat from Iraq in 2011, and was given a permanent protection visa to stay.

"This bloke has no right being here, he's abused the generosity of a country that gave him a new start, and it was absolutely appalling," Mr Morrison told Channel Seven.

"And just because you're on a permanent protection visa, it's a warning to anyone.

"We'll cancel it, and we'll punt you."

Mr Morrison noted that laws he was responsible for as immigration minister, under then prime minister Tony Abbott, made it mandatory for non-Australian citizens to have their visas cancelled if they were convicted of a crime carrying a punishment of more than a year in jail.

The Prime Minister said some 4,000 convicted criminals had been kicked out of the country under the legislation.

Al Bayati will serve his sentence in Australia, before being deported.

It is unclear whether there will be any hurdles in deporting Al Bayati back to Iraq, and whether Iraq would accept him back.

Previous attempts to kick convicted criminals out of the country have been met with legal challenges through the Administrative Appeals Tribunal (AAT), and subsequent appeals through higher courts.

Shadow Attorney-General Mark Dreyfus said the law was clear that there was no place for someone who had committed such crimes to remain in Australia.

But he took exception to any suggestion from the Coalition that Labor was somehow responsible for the situation, given Al Bayati arrived while the party was in government.

"He seems to be implying that immigration ministers have to foresee the future," he said.

"And if he is saying that, then he needs to be considering whether he's accepting responsibility for every single one of the thousands of arrivals in Australia, who he as Immigration Minister, issued a visa to."