Winston Peters has been ordered by a judge to answer questions about whether he received a letter from the Ministry of Social Development (MSD), asking him to check the details he had supplied about his living arrangements, three years before discovering he'd been overpaid.
Court proceedings are underway after a leak to the media about a superannuation over-payment to the NZ First leader and deputy prime minister during the 2017 election campaign.
He was overpaid $18,000 over seven years because he was listed as being single, when he was in a de facto relationship with his long-term partner.
At the time he said he was unaware he was being overpaid and repaid the outstanding amount.
In High Court documents, Crown lawyers posed questions about whether he received a letter in 2014 asking him to check his superannuation details and "contact MSD as soon as possible" if it was incorrect, including his relationship status listed as "single".
In response Mr Peters said he had no recollection of receiving the letter but said he did "not doubt [he] would have received it".
"I note the letter's contents and given nothing had changed since I applied for National Superannuation, I doubt I would have given it anything but a cursory glance.
"I had no reason to think the details would be other than correct as there had been no change in my life relevant to the National Superannuation payment."
A further question was: "Did you contact MSD in response to the letter dated 18 March 2014? If you did, provide details of the communication with MSD".
The judge said he needed to confirm whether or not he did contact MSD, even within the context of saying he couldn't recall the letter, and that a "simple yes/no is all that is required".
The full hearing of the case Mr Peters is taking against National MPs Paula Bennett and Anne Tolley, the Attorney General (on behalf of MSD), former MSD chief executive Brendan Boyle and State Services Commissioner Peter Hughes is due to start at the High Court in Auckland on 4 November.