People who bought tickets online are still waiting to know if they won nearly 24 hours after last night's big $50m draw - but Lotto insists the technical glitch hasn't affected the integrity of the game.
Lotto NZ has apologised for the delay, which it was said due to the "sheer volume" of tickets purchased and the fact Lotto sold "more online tickets than ever before".
Currently the MyLotto site states the online store is open from 6pm tonight, but it may open sooner if possible.
Lotto NZ Chief Executive Chris Lyman said the game's integrity hadn't been affected by issues with the site.
"While we have had some issues with slow processing speeds, and poor customer experience, I can provide absolute assurance that the integrity of our games have not been impacted," he said.
Lotto NZ has seen a surge in online players since March, with the number of people playing online increasing by 33 per cent.
"We have significantly more people buying tickets online now than ever before. Nearly 200,000 people have registered to play online since 25 March – to put this into perspective, this is the number of new online players we would expect over a two-year period, not four months.
"This week alone 32,000 people have registered to play online, with around half of those from the Auckland region."
MyLotto cannot open until later today because all of the winning tickets need to be processed first, Lyman said.
"What's really important is that we pay our winners their prizes – and there are a lot of winners! In fact we've never had so many.
"Not only did 10 players share the $50 million prize, but hundreds of thousands of other people won prizes across all of our divisions."
After last night's whopping $50 million "must win" draw, the result could not be immediately published.
Only this morning was Lotto able to announce how many winners were sharing the haul and where they had purchased their tickets.
Lotto later confirmed between 4000 and 5000 tickets were being purchased per minute for the $43 million draw, which then jackpotted to $50m for last night's draw.
Lyman said the company was making a "substantial investment" in upgrading MyLotto in response to a growing demand of online players.
"The current website is ageing, and the upgrade is required to meet higher demand online," he said.
"While this work is underway we have been making interim improvements. However, regrettably there have been some issues on MyLotto.
"This has in turn resulted in some pretty poor customer experiences, and for that I sincerely apologise."
Prior to the lockdown in March, 25 per cent of Lotto NZ's sales were online and 75 per cent were in-store.
"For last night's $50 million draw around 40 per cent of sales were online," Lyman said.
"We sold around 2.5 million tickets for last night's draw, and over a million of those were online. This is the most tickets we have ever sold online.
"This slowed down our processing significantly, and unfortunately led to delays."
It is not the first time there have been major issues with the MyLotto website after a significant draw either.
On Wednesday the site and app crashed after it became overwhelmed with people trying to buy tickets.
Work to upgrade MyLotto will ensure the back-end processes are more robust, and able to deal with higher traffic on the site. Lotto NZ is also planning a full replacement of its gaming system in 2024.