New Zealand First leader Winston Peters has admitted he was overpaid the pension and has had to pay the money back.
The 72-year-old has confirmed the overpayment in response to media inquiries.
Mr Peters said he had been receiving superannuation since early 2010 when he and his partner went into a Social Development Ministry office to apply for the pension.
He said he received a letter from the ministry in July this year, saying he'd been getting a small fortnightly overpayment.
Mr Peters said while it was unclear how the error occured, he immediately contacted and met with the ministry's area manager and corrected the overpayment within 24 hours.
He said the matter had been put to rest.
The ministry has told RNZ it cannot comment until it gets a privacy waiver from Mr Peters.