Legislation setting up a monitoring regime for deported New Zealand detainees arriving back into the country has just passed its final reading under urgency.

Photo: RNZ / Alexander Robertson

A charter flight carrying about 20 people with criminal convictions is expected tomorrow from Australia and the Government has been rushing to make law changes before the flight lands.

The legislation passed with the support of all parties except the Greens, who abstained.

Earlier today, Justice Minister rejected any suggestions the legislation was a last-minute rush job.

Ms Adams told the House she had been working on getting the regime in place since earlier in the year.

"It's absolutely absurd - this piece of work has been going at pace since it was first raised with me. That's more than the Labour Party can say, when they had serious offenders coming into this country, all the way through their time in office, and didn't do a thing."

But Labour's Jacinda Ardern said it was a sure sign the bill had been rushed when the minister had been talking to the opposition about it only in the past weeks.

"I acknowledge that the minister gave us a call and shared with us various iterations of the bill, but the fact that we were getting amendments the morning this bill came to Parliament demonstrates part of the problem that we have with the process."

Meanwhile, Australian Federal Police working to identify ringleaders in the riot at the Christmas Island detention centre now have a core group of suspects.

RNZ News has been told the group does include New Zealanders.

An estimated $10 million worth of damage was done in the riot, and police have been interviewing centre staff and detainees, as well as forensically reviewing security camera footage.

Up to thirty New Zealanders have been forcibly removed from Christmas Island since the riots, with roughly two thirds of them being held in the maximum security Casuarina Prison near Perth.

It is believed the New Zealanders most likely to face charges over the riots were now in the jail .