A High Court judge has referred to the Court of Appeal his decision to throw out 21 charges against members of the Red Devils gang based in Nelson.
Justice Simon France put a stay on serious charges against the gang members in October after he said the police had seriously abused the court process.
In a covert investigation into the gang, police faked the arrest of an undercover officer, who then went on to appear before a judge and be represented by a lawyer, neither of whom were told the full details of the operation.
The Crown appealed against Justice France's stay on the charges.
He says the question of whether the stay was the appropriate remedy is a question of law and needs to be referred to the Court of Appeal.