Health Minister Chris Hipkins says if there is any evidence of price gouging items such as masks the Government would "like to know about that".
Hipkins spoke on the matter at Saturday's 1pm press conference, saying the issue of price gouging came up during the last lockdown.
He instructed people how to report it when they see it.
"MBIE [Ministry of Business, Innovation and Employment] set up the Price Watch website to monitor that so if people have concerns use that facility to make sure that you're reporting any such behaviour."
Hipkins said the Government has been working "very closely" with supermarket chains to ensure the distribution of masks "is a good one".
If you would like to report a price increase, you can do so here.