Court success ... Derek Wainohu launched the bid in 2010.

Court success ... Derek Wainohu launched the bid in 2010. Photo: Kate Geraghty

Bikies have scored a victory over the NSW government, securing a High Court ruling that a tough law designed to break up their clubs is invalid.

In an 83-page judgment, the High Court ruled today that a Hells Angel's challenge had been successful and the NSW law had been declared invalid, a registrar at the High Court in Canberra said.

The NSW Attorney-General's office confirmed the decision.

The NSW government introduced the Crimes (Criminal Organisations Control) Act in 2009 following the death of Hells Angel associate, Anthony Zervas, during a violent brawl at Sydney Airport.

The law allowed the police commissioner to ask a NSW Supreme Court judge to declare bikie gangs criminal organisations and then seek control orders banning individual members associating with one another.

Derek Wainohu, a prominent member of the Hells Angel Motorcycle Club, launched a bid in 2010 on behalf of Sydney chapters of the club to have the law declared invalid.

Mr Wainohu's case hinged on the argument that the Crimes (Criminal Organisations Control) Act infringed individual liberty and undermined the integrity of the NSW Supreme Court.

The law was introduced to the state parliament by former Labor premier Nathan Rees on April 2, 2009, about one month after Mr Zervas's death.

The legislation was based on similar laws in South Australia, parts of which were declared unconstitutional in late 2010.

A spokesman for NSW Attorney-General Greg Smith said: "We acknowledge the court's judgment and we'll be examining the verdict."

He declined to comment further.

The court ordered NSW police to pay Mr Wainohu's legal costs.

Mr Wainohu's lawyer, Wayne Baffsky, has previously said it was extremely important that the Hells Angels' legal challenge succeeded.

"This legislation has the potential to destroy lives, both individual and family," he said in a statement when the challenge was launched.

"It also has the potential to destroy democratic society if misused."