By Andrew McRae of RNZ
A business case will test the feasibility of a train that could complete the 125km trip in half the current time.
It Transport Minister Phil Twyford said Cabinet approved an investigation to the viability of a rapid rail connection getting between the two cities.
The study is expected to be completed next year.
Twyford said it would look at "160km/h, modern tilt trains that would connect Hamilton with Auckland's downtown Britomart station in an hour".