A man convicted after a "bogus" police prosecution has had his case thrown out of court.
The Supreme Court judgment, released today, quashed Trevor John Momo Wilson's drug-dealing convictions and declined to order a retrial because "it was an abuse for him to have been proceeded against at all".
Wilson was initially charged with five counts relating to the possession, supply and sale of certain drugs.
He was one of 21 defendants facing charges arising from an extensive police investigation into the activities of Nelson motorcycle gang the Red Devils.
The defendants faced a total of 151 charges, including participation in an organised criminal group, supply of methamphetamine or other drugs, conspiracy to cause grievous bodily harm, threatening to kill and other offences against the Crimes Act 1961 and the Arms Act 1983.
The police investigation involved the use of undercover officers, interception warrants and other investigative tools.
Part of that undercover operation, referred to in court documents as the "the bogus warrant/bogus prosecution scenario", ran for around nine months from late May 2010.
It involved the use of a bogus search warrant and the bogus prosecution of an undercover officer.
The Crown accepted it involved "serious misconduct by the police".
In 2012 Wilson pleaded guilty to supplying LSD, conspiring to sell party pills, selling cannabis, conspiring to sell cannabis and possession of LSD.
However, police were found to have acted corruptly after a staged search for evidence against an undercover officer.
Today a majority of the Supreme Court decided it would be unfair, and a miscarriage of justice, to allow Wilson's convictions to stand. The majority also considered that no retrial should be ordered.
Supreme Court Chief Justice Sian Elias, in a separate judgment, agreed Wilson's convictions should be quashed and that there should be no order for a retrial.
Wilson was sentenced in September 2012 to two-and-a-half years' jail on the charge of supplying LSD and concurrent terms of imprisonment of a year on the other charges.
Of all 21 accused, Wilson was the only one to plead guilty.
The other co-accused applied to the High Court for a stay of prosecution on the grounds the actions of the police during the investigation were so against acceptable practice they amounted to an abuse of process.
In October that year, Justice Simon France in the High Court issued a stay on all prosecutions of the 21 accused after police were found to have committed "fraud on the courts".
Police were found to have manufactured a fake search warrant, created an invented signature of a court official to back it up then staged a false arrest of an undercover agent.
Wilson appealed his conviction after the stay of prosecutions that allowed his co-accused to walk free.
The Crown opposed the appeal, but in a Court of Appeal judgment Justice France allowed it.