Energy Minister Simon Bridges ducked the issue yesterday while spokesmen for Mighty River Power and Genesis Energy declined to comment.
But electricity industry watchdog Molly Melhuish says Bertram is bang on, and the Government is not doing enough to protect consumers. "This is the only country in which the regulator protects investors instead of consumers," she says.
Bertram's research shows most other Western nations have had little growth in power prices in recent decades.