CCTV footage of Maria Brown at the Smithfield RSL. Photo / Supplied

CCTV footage of Maria Brown at the Smithfield RSL. Photo / Supplied

It was almost midnight in a neighbourhood bar just outside Sydney when two of New Zealand's most notorious exports turned again to an ugly violence.

Mother and son, Maria and Prince Brown, can be seen on CCTV footage from the Smithfield RSL Club muscling their way into the bar, facing down a man wearing a jacket bearing the patch of the Gypsy Jokers gang.

The Browns are with three others, and they cluster around their intended victim. Someone - it's hard to see who in the blur of action - swings an arm and the Joker bends double. A kick this time, and he falls to the floor.

As the victim lies on the floor, arms around his head for protection, Prince Brown can be seen kicking him three times in the head "with increasing force, ending with what appears to be a running kick", an official report describes. Prince Brown will say his part in the assault was "self defence", a claim found to be "untenable".

Before the assault in the middle of last year, the tiled floor is clean. After, it is covered in blood, although it is hard to see whose blows caused the bleeding.

Maria Brown hands the Joker's jacket to her son, who drops it and tramples it underfoot.

For Maria and Prince Brown, it was a typical mother-and-son outing. But for the New South Wales police, it was the point at which their patience finally ran out with a pair of Kiwis who had claimed Australia as home.

The Browns have been exiled from a nation whose roots are those of exiles; criminals banished to the world's largest island.

They are among the latest New Zealanders banned from Australia - a growing number who have fallen to increasingly aggressive attempts by Australian authorities to be rid of unwelcome visitors.

They have just lost their latest appeal against deportation and are due back in New Zealand at the beginning of March. When the deportation order was handed down NSW police commissioner Andrew Scipione declared: "People who do not respect the laws of this country do not deserve to enjoy the privilege of living here."

And now they are heading back to New Zealand.

Maria Brown moved to Australia in 1997. Although born in Samoa, Brown used the passport of her adopted New Zealand after gaining citizenship. Brown moved to the suburb of Airds, southwest of Sydney, where she came to dominate the local criminal scene, styling herself as the Queen of Airds. A year later, her son Prince joined her from Auckland.

It took 18 months for each of them to appear before the courts. Maria Brown faced drug and stolen property charges in 1999, and Prince Brown a slew of charges in the juvenile courts a year later. Evidence of these and other convictions were presented at an appeal against deportation this month.