Australian Migration Act 1958, which has accelerated the deportation of criminal non-residents from Australia since 2015 Gang patches Some political leaders including the-then Māori Party co-leader Pita Sharples have called for gang patches to be made illegal. In 2009 the Wanganui District Council voted to ban gang patches, but it was overturned following a judicial review instigated by the Hells Angels. The council tried again in 2011, this time restricting the ban to just the central business district, malls and parks. A law banning gang patches from government and public buildings was introduced in 2012 by National Party Member of Parliament (MP) Todd McClay. Police welcomed the law, but critics such as Mana Movement MP Hone Harawira claimed it was racist against Māori. It was passed as the Prohibition of Gang Insignia in Government Premises Act 2013, and has been in force since August 2013. Incarceration rates Gang members account for a rapidly increasing proportion of incarcerations in New Zealand. A New Zealand Ministry of Justice study showed that in 1991 just under 80% of prison inmates had no gang history, and just over 90% had no current gang membership. Of the prison population, 4% were members of the Mongrel Mob and 4.3% former members, while 3.6% were current and 3.2% former members of Black Power. No other gang had more than one percent of the prison population. A similar study in 2003 showed that 11.3% of prison inmates were gang members. Of these, 35% were Mongrel Mob and 33% Black Power, with no other individual gang having more than 5% of the imprisoned gang population. As of April 2013, gang members and affiliates account for over 30% of inmates, with over 10% of New Zealand prisoners being Mongrel Mob members. Gang membership According to the 2007 book Gangs by English journalist Ross Kemp, New Zealand had more gangs per head than any other country in the world, with about seventy major gangs and over 4,000 patched members in a population of 4 million people. In 2019 the Police recorded 6,500 patched or prospective gang members in the country, with the ten main gangs being the Head Hunters, Bandidos, Hells Angels, King Cobras, Black Power, Mongrel Mob, Tribesmen, Rebels, Devils Henchmen and Highway 61. In October 2019, Stuff reported that New Zealand gangs seemed to be recruiting members at a greater rate than the New Zealand Police. Between October 2017