Four private tertiary establishments have had their intake of international students suspended after "serious" breaches of their obligations.
A joint investigation by the New Zealand Qualifications Authority and Immigration New Zealand found students studying for less than the minimum 20 hours per week, misleading or poorly maintained attendance records and fee discrepancies.
The institutions were identified as the National Institute of Studies (Auckland, Tauranga, Otahuhu and Christchurch), EDENZ Colleges Ltd (Auckland and Tauranga), Aotearoa Tertiary Institute (Otahuhu) and the New Zealand School of Business and Government (Auckland, Christchurch and Wellington).
Immigration general manager Peter Elms said the breaches were serious.
"It is concerning that these private training establishments (PTEs) have been operating in a manner that falls well below minimum standards."
He said the suspensions would not be lifted until they were fully compliant.
A total of 842 international students are enrolled at the four institutions but Mr Elms said they would not be affected by the suspensions, which related only to new or undecided visa applications.
All four institutions had failed to deposit student fees in full into their student fee protection trust accounts.
NZQA spokesman Tim Fowler said the actions of the four PTEs had undermined the integrity of New Zealand's export education industry, which had an enviable reputation and was worth around $2.7 billion a year to the economy.
"The vast majority of PTEs have an excellent reputation and do a very good job," Mr Fowler said.
"This action sends a strong message to the industry that these sorts of breaches will not be tolerated."