The anti-fraud committee in New Caledonia says it has checked 112 businesses in the first six months of operation.
The committee was formed by the French High Commission, the president of New Caledonia and the public prosecutor to coordinate the fight against illegal work and fraud affecting public finances.
Its work also involved the social security agency Cafat.
In a statement, the High Commission said it examined the restaurant, private security, transport and construction sectors.
It said there were 34 cases of improperly declared work.
It also said there were 14 breaches of the code regulating private security companies.
The committee said it remained determined to fight fraud, which it described as a scourge on society and public finances.
The statement didn't mention what sanctions were taken in response to the offences.