Police Minister Judith Collins said the act had been working effectively.
"Police have been extremely successful in investigating and seizing the dirty money of criminals and gangs since the Government passed this legislation.
"Police use all of the tools at their disposal, including the legislation which has strengthened their ability to go after the assets and profits of organised criminals."
She said 88 per cent of restraints and 96 per cent of forfeitures have been linked to drugs and/or organised crime.
"Gangs, organised crime, drugs and family violence drive much of police daily workload, and reducing these harms and crimes is a priority for the Police Commissioner and the Government."
She said the outcome of cases was determined in court.
Lawyers said although the overall intent of the law is positive but the finer points should be questioned.
Whangarei lawyer Wayne McKean said this law strikes at fundamental principles of justice, including someone being presumed innocent until found guilty.
"The overall purpose of the legislation is justified, to take ill-gotten gains off people, but I think the way they're doing it is not justified; lowering the standard of proof, and having reverse onuses in the system."
He said the owner of the assets must prove in court they lawfully own the property in question, rather than the Crown proving the person obtained them illegally.
Assets acquired wholly or in part as a result of suspected criminal activity can be forfeited to the Crown on "the balance of probabilities" which is a lower level than the criminal standard of proof of "beyond reasonable doubt".
Mr McKean said he didn't expect the law to be effective in Northland.
"I don't agree with it. This law is not going to reduce gang activity [in Whangarei]. What it may do is that it might mean the Government gets more money from people."
The Northern Advocate sought the Police Minister's response to Mr McKean's comments but she did not directly address his concerns.
"The Criminal Proceeds Recovery Act enables police to confiscate the proceeds of crime and all money forfeited under the Criminal Proceeds Recovery Act can be made available for agencies to fund new, improved or expanded projects," she said.
Lawyer Graeme Edgeler said he also questioned taking someone's house, cars and savings without criminal activity being proven.
"The Government should not have the power to punish you unless it can prove to a pretty high standard that you've actually done something illegal," Mr Edgeler said.
"Even if there's a 49 per cent chance you're completely innocent, that the Government can take everything you've worked for away is pretty serious."
Green MP and spokesman for criminal justice David Clendon said the party opposed the legislation when it came into law and still opposed it.
"People can potentially lose homes without any rigorous proof being required through the justice system that they have actually offended or done some wrong, and that's inconceivable," he said.
"That's really slippery-slope stuff."