The Civil Aviation Authority is investigating claims that a number of aviation operators in adventure tourism are trying to get round safety regulations.
Some companies are said to be taking people on so-called "trial" flights to see whether they want to learn to fly, when they are really commercial scenic flights which require operators to get new certification.
Stricter drug and alcohol and other safety regulations were brought in after last year's Carterton balloon crash, in which 11 people died, and the 2010 Fox Glacier plane crash that killed nine people.
CAA acting director John Kay would not give details of how many cases it is investigating but said the authority will take action against operators trying to get round the regulations.
"If there are people out there operating in that space of using a trial flight as a guise for what is otherwise a 115 activity - an adventure aviation activity in this context - that is something we take quite seriously, and as I say we've got a number of activities ongoing around that area at this point."
The head of a Wanaka-based scenic flight company says some operators are falsely describing commercial scenic flights as trial flights.
U-Fly chief executive Wayne Allanson says it is a danger to the tourism industry and he wants the authority to take stronger action.
"They need to actually stop what's happening and get these guys certificated before they continue their operation. Unless its actually fixed there will be an accident that comes out of this."
Aviation Industry Association executive Irene King says the easiest way to tell if an aircraft is being used to conduct trial flights is whether it has dual controls and a pilot instructor operating the plane.
Ms King says the allegations are hard to believe, because most aviation companies are working with the new rule, but if there is an issue the CAA investigation will deal with it.