Winston Peters admits taking extra pension payments

New Zealand First leader Winston Peters has admitted having to pay back a pension overpayment, after being contacted by Newshub.

When contacted on Saturday, Mr Peters initially refused to confirm he had been overpaid the pension since 2010, going as far as to say someone was "seriously misleading you, mate".

"Oh well, you know, you go with your source and see how it looks," he said.

"I'll say it to you one more time real slow... You're not going to get any response from me at all."

But on Sunday night he issued a statement called "A mistake that was fixed," and said not only was he overpaid, but he paid the money back in July this year.

In the statement, Mr Peters said he had applied for pension in 2010 "in the company of [his] partner" and a senior Ministry of Social Development official.

"In July of this year, I was astonished to receive a letter from the ministry to advise there was an error in my superannuation allowance and a request that I meet with them," he said.

After "immediately" contacting and meeting up with MSD's area manager, Mr Peters said they agreed there had been an error.

"It was unclear on both sides how the error had occurred leading to a small fortnightly overpayment," he said, adding he paid the money back once he found out.

"I subsequently received a letter from the area manager thanking me for my prompt attention and confirming that the matter was concluded to the ministry's satisfaction."

But when contacted by Newshub on Saturday regarding the issue, Mr Peters said: "Well look, I'm not going to be answering questions like this here in this election.

"If you ask me if I owe anybody any money at all the answer is no, full-stop," he said.

"I'm not going to respond to malicious statements that aren't true."

Mr Peters' admission comes after former Green Party co-leader Metiria Turei revealed she deliberately defrauded WINZ so she could have enough money to raise her young daughter.

Ms Turei's admission was in July - the same time as Mr Peters now says he was contacted by MSD about his own mispayments.

Ms Turei resigned from Parliament several weeks later, saying her family had been put under "unbearable" scrutiny after she made her declaration.

At the time, Mr Peters said it was a tough legacy to leave behind.

"If it had been handled at the start properly with some sound advice, then this would not have happened," he said.

It's not yet known how much he was overpaid and Mr Peters refused to give details when contacted by Newshub on Saturday, but on Sunday he said he "corrected" the error and overpayment within a day of finding out about it.