Consumer watchdog the Commerce Commission is sueing ticket reselling site Viagogo.
The comission is set to commence civil proceedings in the High Court under the Fair Trading Act for breaching consumer law.
It will seek an injunction to restrain Viagogo from further breaches.
The commission alleges Viagogo made false and misleading claims, acting as an "official" concert ticket seller when it was not, labelling tickets as limited or about to sell out and claiming consumers were "guaranteed" to receive valid tickets to events.
It also alleges Viagogo's ticket pricing was misleading, saying 'headline' prices were unobtainable because of the addition of GST and various fees added.
The comission joins a string of international enforcement agencies who are bringing similar cases against Viagogo.
The Swiss compay is now facing court or enforcement action in Switzerland, Germany, France, Spain, the UK and Australia.
It has already been fined in Italy and sued by football association FIFA, banned from selling tickets to various World Cup Events.
Since the beginning of last year the comission has received more than 400 complaints about Viagogo.
Commerce Commission consumer head Stuart Wallace said he was pleased to launch legal proceedings.
"We acknowledge that this has been a longstanding investigation, and in large measure that is because of the complexity of pursuing a case against an online trader based offshore," Wallace said.