State and federal ministers and attorneys-general requested an amnesty be considered by senior officials in the National Justice and Policing Senior Officials Group last year.

These officials gave a unanimous in-principle support for an amnesty last month.

State ministers must agree to proceed, however, support for an amnesty is strong and it is understood the timing will be settled before the end of the year.

Victoria's Police Minister Lisa Neville said the state government would support the move.

"We are working with our State, Territory and Commonwealth colleagues on how it will be rolled out. The Commonwealth is leading this work and the details are still to be settled," Ms Neville said.

This week, a Fairfax Media investigation revealed shootings are now a weekly occurrence in Melbourne and gun-related crime has doubled since 2011.

There are also more legally owned firearms in the country than before the 1996 Port Arthur massacre, which sparked the original national amnesty and buyback.

A new amnesty has been backed by prominent children's safety charity, The Alannah and Madeline Foundation, which was founded in honour of two young sisters, aged six and three, who were murdered at Port Arthur.

"The Australian community cannot get complacent about this -- for people to feel that it's all done and fixed," chief executive Lesley Podesta said.

The 1996 scheme led to the voluntary surrender of more than 700,000 firearms.

More than a million new weapons have been legally imported since.

State shadow Police Minister Edward O'Donohue warned a new scheme would not target criminals who have access to illegal, high-powered weapons.

"Any response from Victoria Police and (state) government should be focused on this cohort, not lawful guns owners," Mr O'Donohue said.

Firearms Safety and Training Council general manager Gary Bryant agreed.

"Licensed firearm owners and users are not the problem. The problem are criminals and criminals do not respond to regulatory environment. They don't care about regulations," Mr Bryant said.

Federal Justice Minister Michael Keenan said legislation that doubles the maximum penalties and provides a mandatory five years jail for firearms trafficking will be introduced in parliament this week.

"The illegal trafficking of firearms is a deadly crime and just one illegal firearm is a huge threat to the safety of Australians," Mr Keenan said.

The size of the illicit market and how guns get there is a contentious subject.

Some authorities have argued that many guns used in crimes are illicit weapons not turned over in 1996; a source known as the "grey market". Criminologists estimate at least 1500 guns are stolen from legal owners every year.

A senior law enforcement source says the "diversion" of newly imported weapons, either through theft or illegal sale, is one of the biggest sources of black-market firearms.

And despite Australia's strict border controls, the smuggling of high-powered military-style firearms is also a growing problem.

Gun-control advocates have also warned that any amnesty or new regulations must come with a broad national conversation about why they are being undertaken in order to ensure public support.

"One of the things we know from the previous buyback is that it was accompanied by an enormous amount of community education, public information, public debate and bringing people together within the community around saying 'this is how we want our country to be'. That's really critical," Ms Podesta said.