Winston Peters is back in court today, continuing the battle over the release of his superannuation overpayment details

Justice Geoffrey Venning last year rejected Peters' claim of a breach of privacy in the High Court, and he was ordered to pay nearly 320-thousand dollars in costs.

But he has brought the case back to court in Wellington's Court of Appeal this morning, arguing against the judge's decision.

In court today, Peters' lawyer Brian Henry says the superannuation application shouldn't have been processed in the first place, because it was incorrectly filled out.

He says MSD bosses breached privacy, by revealing details to Government ministers when an investigation had already revealed the mistake wasn't a result of an intention to mislead or defraud.