A man convicted in a botched police undercover drugs bust has had his convictions quashed by the Supreme Court because the other 20 people charged had already had their trial aborted.
Trevor Wilson was the only one to plead guilty after police targeted the Red Devils bikies in Nelson in 2010.
But they used false charges against an undercover officer, a false search warrant and approached the then-chief district court judge to sanction what they were doing.
One of Mr Wilson's lawyers, Golriz Ghahraman, said she hoped the police would learn from the case and that it would not happen again.
"It was the police treating the court as an arm of its own investigation, whereas the police should just be a party like anyone else before the court, so that independence was undermined. I would hope that it acts as a deterrent."
The case led to the police overhauling their rules about undercover operation.