The Financial Markets Authority says it will use the full range of its powers to pursue cases when large numbers of investors have been left out of pocket, or when there's been criminal offence.
Less than six months into its regime, the FMA has issued an outline of how it will enforce rules in the market.
Chief executive Sean Hughes says that by setting out its policy about how and when it will take action, the FMA wants to send a very clear signal to the market as to the sorts of conduct regarded as unacceptable and the sorts of circumstances that will motivate the authority to take action.
He says he hopes this will bring confidence back to the market.
The FMA is better resourced and has a wider remit than its predecessor, the Securities Commission, from which it inherited investigations.
Last week the FMA said it is pursuing investigations into 16 finance companies, including South Canterbury Finance, Hanover and Strategic Finance.