If SkyCity was deprived of compensation for an early end to the Gambling Act concessions it will receive under the deal with National, "certain overseas investors in SkyCity may have arbitrated rights to compensation under bilateral investment treaties and free trade agreements".
Mr Franks goes on to say that should a future Parliament make changes to the Gambling Act which effectively undermined the deal with SkyCity, its liability would probably not extend to a penalty for the law change "but it would permit compensation for genuine losses suffered from investment in reliance on the state's contract."
Mr Franks' analysis also suggested the preliminary deal or "heads of agreement" signed by the Government and SkyCity last month "exhibits an approach to procurement that skirts important constitutional safeguards."
The Government was in effect selling dispensations from the Gambling Act to SkyCity which were not available to others in return for the convention centre.
"The ability to "purchase" a dispensation from regulation sits uncomfortably with the rule of law", Mr Franks said.