The programme designed to protect SkyCity gamblers from addiction has never been reviewed - even though having it is a condition of the casino's licence.
The Gambling Commission says it has been too busy, so it has put the review of the "responsible gambling programme" on the "back burner".
The admission comes amid negotiations between the Government and SkyCity over the $350 million national convention centre. SkyCity has offered to build the centre in return for concessions on gambling.
It wants early renewal of its licence, more gambling machines, automated gaming tables and an increase in the number of other table games.
Economic Development Minister Steven Joyce - whose officials are negotiating with SkyCity - has previously given assurances over the Government's focus on problem gambling.
He told Parliament last year: "The Government will keep a careful eye on SkyCity, as it always does, to ensure SkyCity upholds its part of any bargain in terms of continuing harm minimisation work."
A spokeswoman for Mr Joyce said last night the minister had checked with the Gambling Commission, which advised the casino had a host responsibility programme.
"Their licence requires them to report to the Gambling Commission every six months on the implementation of the HRP. The Gambling Commission has been satisfied with these reports and thus has seen no pressing need to review the HRP."
The casino licence granted to the company required the commission to review the programmes every two years. It also ordered SkyCity to make its own reports to the commission every six months.
The requirement for the review was underscored in a 2007 commission decision which said the casino's responsible gambling programme was "an important source of the detailed legal obligations" for SkyCity.
Commission executive director Blair Cairncross said it was hoped the commission would be able to review SkyCity's programme early next year.
"The commission was supposed to review it every two years but that got put on the back burner as other work took precedence."
Green Party co-leader Metiria Turei said the reviews were five years late and the commission had missed two review periods.
"The Gambling Commission has made a mistake in not keeping up with its obligations to review SkyCity."
The Government's promised careful watch on SkyCity's obligations to problem gamblers fell flat.
"It is extremely worrying the Government says they will be keeping watch on these programmes and they haven't. It puts gamblers at SkyCity even more at risk."
Labour leader David Shearer said Mr Joyce's claim of keeping a "careful eye" was not reflected by the facts.