"The amount of money that is being siphoned out of New Zealand's tourism industry is unimaginable," Pro Guides NZ chairwoman Claudia Duffy said.
Kickbacks, charging tourists for visiting a public park or to sit in the front seat of a bus, were causing irreversible harm to the tourism industry.
Paying cash to hotels for reduced rates while charging clients a mark-up, collecting commission from tourist attractions, and developing "preferred business relations" with shops and restaurants in exchange for commissions and discounts, was also common.
In recent years, there had been a proliferation of Asian and European-based guides flouting New Zealand laws by leading illegal tours around the country.
A "popular approach" was for overseas tour operators to send employees on a New Zealand tour. They would make contact with accommodation, transport and tourism operators.
The employees would then return as guides, but without the appropriate work visas, or endorsed vehicle licences. They were instructed to "act stupid" when dealing with authorities over their licence and immigration status, the Auckland-based coach tour guide said.
"These activities are not only eating away at the integrity of New Zealand's immigration and work laws, they are also seriously depriving local guides of employment."
The cost of hiring a qualified New Zealand guide was between $250 and $350 a day, plus accommodation and food for multiple day tours, Mrs Duffy said.
The competition from illegal operations made it difficult for self-employed guides, who typically worked from September to May, to make a living.
Of particular concern was the "dangerous scenario" of foreign guides driving passenger vehicles without an endorsed licence, with rental companies often not sighting appropriate documentation.
"It is just an accident waiting to happen." Approaches to agencies such as Immigration, police, New Zealand Transport Association and the Conservation Department, which administered concessions, had been unsuccessful.
"We are getting fed up with it. We don't need new laws - we need law enforcement."
Immigration New Zealand risk and integrity intelligence general manager Steve Stuart said any foreign national found working in New Zealand in breach of their visa could be deported.
In the year to the end of April, 667 people were deported and a further 950 people left voluntarily following intervention.
In 2009, a German national was discharged without conviction after admitting leading an organised tour in Abel Tasman National Park without a concession.
