Trans-Tasman casino operators SkyCity will shut its downtown Auckland gambling floors for five days as a punishment for failing to meet harm minimisation obligations.
The shutdown, which is likely to cost SkyCity $NZ5 million ($A4.5 million), was announced on Thursday after a long-running investigation.
New Zealand's internal affairs department (DIA) found 23 instances where a customer was able to gamble non-stop without detection by SkyCity, contrary to licence rules that require them to identify and assist problem gamblers.
SkyCity has voluntarily agreed to the closure as part of the probe resolution.
"The resolution agreement is an unprecedented result," DIA gambling director Vicki Scott said.
"This is the first voluntary closure of a casino and is the longest suspension of operations in a casino under the Gambling Act.
"Casinos and other gambling operators have strict obligations when it comes to preventing and minimising harm from gambling, including those relating to continuous and long hours of play."
Chief operating officer Callum Mallett apologised, saying SkyCity's "failings are significant and the company is rightfully being held to account for them".
"We place great importance on host responsibility ... we are deeply sorry for the harm caused to this customer," he said.
Since the failings, SkyCity has rolled out facial recognition technology and plans to introduce carded account-based play in 2025.
"Carded play will allow both us and the customer to monitor how long they've been playing and when they need to take a break. If they play for too long, the card will disconnect and they will not be able to continue playing," Mr Mallett said.
The dates of the closure - down from a 10-day shutdown proposed by DIA in September - are yet to be confirmed.
The announcement of the charges wiped a quarter of a billion dollars off SkyCity's market value on the New Zealand stock exchange, according to Radio NZ, opening trading at $2.33 before closing at $2.02 a share.
Shares were worth $1.53 on Thursday's open, rising to $1.55 after half an hour of trading.
SkyCity operates four casinos in New Zealand - in Auckland, Hamilton and two in Queenstown - as well as SkyCity in Adelaide, and online gambling.
The beleaguered casino operator also admitted fault for failing to meet money-laundering and terrorist-financing obligations on both sides of the Tasman.
In June, it agreed to pay a $A67 million penalty relating to its Adelaide casino, and in May, a $NZ4.16 million ($A3.76 million) fee was levied after a similar probe into its Auckland operations.