Two separate trials of the CovidCard will still go ahead, despite one of its original backers pulling out, government ministers Kris Faafoi and Megan Woods say.
The card uses Bluetooth technology to help with more efficient mass contact tracing and is due to be trialled in Rotorua this month.
But tech entrepreneur Sam Morgan said he did not see how the card could successfully go ahead without his team even though he did not own the technology.
His team had written the software, procured the card design, and organised a factory to make them.
The Ministry of Health's IT team were not up to the task, he said.
Government Digital Services Minister Kris Faafoi said Morgan was not the only brains behind the card and the project was not in jeopardy
"I know Sam is frustrated, I can't control Sam's feelings on a day-to-day basis, but we are committed to making sure we have a trial in Rotorua," he said.
Morgan said the government was taking too long and the CovidCard was being bogged down by bureaucracy and Ministry of Health middle management.
He said he was frustrated the government was again considering using Apple and Google data which was inaccurate and would not work well for New Zealand, for contact tracing.
Faafoi said the government had to take time to consider the best solution, especially as it was likely to cost more than $100 million.
Any decision had to be based on whether the card would work and people would be prepared to use it, he said.
Minister in charge of managed isolation and quarantine Megan Woods said there were two trials of the CovidCard - a community trial in Rotorua and another that the government would use within managed isolation and quarantine facilities for staff and returnees.
Morgan's withdrawal from working with CovidCard would have no impact on the latter, Woods said.
"We are still [in] a position to keep working through [that] and we are working through where that trial will be. We have a couple of contenders of isolation facilities where it will be useful as a tool to track contacts within a facility, but that is quite separate from the Rotorua trial."
Woods said the managed isolation trial had not involved Morgan.
The CovidCard can be worn or carried by people and would send and receive digital signals to and from other cards around it.
That data would then be used to identify those who may have been close enough to someone with Covid to mean they were also at risk.
It would remove the need for people to have to remember - or bother - to use their Covid Tracer App.
The government was also trialling leaving a card in lifts in managed isolation hotels to see if it could successfully trace if people had been in high risk areas.
The Ministry of Health's data and digital director general Shayne Hunter confirmed it was continuing to work with other people in the private sector on the card.
He said it needed to assess how it would work in real life situations.
"The country is dealing with a tricky virus and we need a number of effective tools to fight Covid-19," he said.