Some unemployed and sole parent beneficiaries may have also had their payments wrongly suspended during the Ministry of Social Development's recent botch-ups.

But MSD has not said how many, and did not answer RNZ's specific questions.

Its recent review into two major problems - a legislative error, and processing delays - revealed more than 30,000 welfare payments were incorrectly paused.

The processing delays followed a law change requiring many beneficiaries to confirm their circumstances annually to ensure they remained eligible for their payments.

MSD staff were flooded with paperwork and some of it was not checked in time, so some benefit payments were stopped.

Those affected included more than 2400 main beneficiaries - mostly on the Supported Living Payment - who were left out of pocket before they were backpaid, some by thousands of dollars.

MSD has now confirmed people receiving other main benefits such as Jobseeker and Sole Parent Support may have been caught up in the backlog, too.

Jobseekers must reapply for their benefit every six months.

MSD service delivery general manager Shannon Soughtton said delays in one part of the large organisation may have had knock on effects.

"Some clients receiving other main benefits may have been impacted by processing delays during this period," she said.

"MSD's processing timeframes can be influenced by a range of factors, including seasonal increases in demand, the complexity of a client's circumstances, difficulties contacting clients, or situations where we are waiting for additional information."

RNZ asked how many other main beneficiaries were affected, how long they were without payments for, and the total arrears bill.

MSD did not answer that.

If there were delays in processing someone's entitlement and they were found to be eligible for it, they would be backpaid, Soughtton said.

MSD said in its review of the processing delays it analysed 51,000 client files to identify the potential impact.

But that only included people who were confirming their circumstances, which people receiving Jobseeker or Sole Parent Support do not need to do.

A spokesperson for Social Development Minister Louise Upston said MSD regularly monitored workloads and reallocated resources to help manage demand.

"The minister expects MSD to manage its operational workloads and to keep her informed," they said.

MSD and the minister had previously apologised for the problems.

Labour's social development spokesperson Willow-Jean Prime said Upston needed to reveal the "true scale" of the problems.

She said the minister had overwhelmed MSD's system by introducing the six-month reapplication process for Jobseekers, and cutting jobs.

"This has since backfired badly, causing possibly many more Kiwis to lose their payments," Prime said.