Online tormentors may face even tougher measures than those in Justice Minister Judith Collins' new anti-cyberbullying laws, she says.

A bill, to be introduced to Parliament today, will create a new offence of sending messages or posting material to cause harm, punishable by up to three months in jail or a $2000 fine.

Inciting someone to commit suicide will also carry a maximum three-year jail sentence.

The move comes amid a furore over the "Roast Busters" sex scandal.

However, Collins said the timing was coincidence. She had been working on the bill since an initial announcement in April, and had always intended to put it forward today.

Nevertheless, she was "absolutely" open to further sanctions against cyberbullies, if a select committee thought they were warranted.

She called the legislation "groundbreaking" and said few countries had taken a similar approach.

The legislation did not deal with sexual violation, but would give victims the ability to ask for offending material to be taken down, she said.

Collins did not want to be drawn on the Roast Busters case while it was subject to a police investigation.

However, she did defend shelving proposals by predecessor Simon Power to introduce an inquisitorial trial system for sex offences. She dumped the idea last year, saying it was too tricky to impose a different system for certain crimes.

"I think it is always difficult, whether it is a woman or a man who has been subject to some form of sexual activity, to come forward and to say that they want to make a complaint," she admitted.

"To make it easier would also make it much harder for someone to defend themselves if they are accused of sexual violation."

Sexual violation was an "extremely heavily penalised offence" with up to 20 years in jail, she said.

"You basically have to kill someone to get anything higher than that."

The Roast Busters are a gang of Auckland men who have allegedly lured young girls into group sex then posted video online. Police are investigating and yesterday Prime Minister John Key described reports of their behaviour as "abhorrent".

Collins echoed that view.

"Pack sexual intercourse with a young girl is always abhorrent. It was abhorrent 20 years ago ... it was abhorrent 50 years ago ... It's always been unacceptable.

"Nowadays though, we've got video recording on all of the cellphones that we have and that makes it easy for cyberbullying and other forms of bullying to occur as well."

She also attacked Labour spokeswoman for women's affairs Carol Beaumont for wading into the row yesterday.

While it was appropriate for a politician to discuss policy or the law, she was "appalled" anyone tried to engage "for political reasons".

"Actually what they are doing is stamping all over a police investigation ... their behaviour might well interfere with a fair trial."

Asked if Labour is backing the Harmful Digital Communications Bill, Collins said "only a moron" wouldn't give support.

Labour leader David Cunliffe said the legislation was "useful" and the party would "certainly" support it.

However, it "doesn't go to the core" of the Roast Busters matter, which was a reluctance among victims to come forward.

It was a "great shame" that Collins dumped Power's reforms, Cunliffe said, and called for her to reconsider.

Labour backed, for certain crimes, the ability for victims to give anonymous evidence and have questions fielded by a judge rather than a lawyer, he said.

He also had concerns about police handling of the matter and wanted to know what steps were taken to protect those at risk and warn the community and schools.