At least four of the 13 finalists are already signed with an agency and have participated in numerous catwalk events and campaigns, despite rules which state contestants must not have modelled in a "national campaign in the last five years".
The application forms for the show also state any models must be able to terminate existing agency contracts.
Dunedin twins Elza and Nellie Jenkins (17) are signed with Ali McD models and are among the 13 finalists.
Agency director Aliana McDaniel said four of her girls had made it through to the final group, and she was not concerned that their participation meant they would switch to sign with 62 Models & Talent, owned by Top Model host Sara Tetro.
New Zealand's Next Top Model producer Anna Lynch said she was "perfectly happy" with some contestants having more experience than others.
"If you are tall and thin in New Zealand, chances are you will have been asked to walk in a show."
Ms McDaniel was told the "highest quality girls" who made it to this stage of the competition were from her agency.
Show spokesman Jade Rook said between 500 and 1000 women auditioned for the show, and about 200 were chosen as possibilities.
They were whittled down to 33, and then down to the 13 finalists who will move into the model house in Auckland, where most of the show will be shot.
The series will screen later this winter.
- New Zealand's Next Top Model premieres Friday, August 6, at 7.30pm on TV3.
