Mr Brown is a director and shareholder in Te Tai Tokerau Minerals which has two permits northwest of Kerikeri. Australian company De Grey Mining has two permits southeast of Paihia. A third company, Waimatenui Exploration, has a permit for an area about 30km south of Kaikohe. Combined, the five areas to be explored cover more than 16,000ha.
Other than gold and silver, De Grey will explore for lead, copper, zinc and mercury and Waimatenui will look for copper, nickel and zinc.
The five- to 10-year exploration phase will require resource consents, but those are issued by the Northland Regional Council rather than the Far North District Council which Mr Brown heads.
Mr Bridges said issues of probity were examined before the permits were issued and Mr Brown didn't receive any favourable treatment.
Officials estimated the activity could result in expenditure of $7 million to $13 million in the first three years.
Mr Brown said his company was likely to seek capital in about a year's time to fund its exploration, hopefully from investors within the region.
Labour's environment spokeswoman Maryan Street welcomed the prospect of more jobs but she wanted to find out more about potential environmental risks.