The Qualifications Authority is moving to stop tertiary institutions that enrol foreign students from compressing a week's teaching into two or three days.
The authority's deputy chief executive, Grant Klinkum, said the practice was inappropriate and could allow foreign students to work more than the 20 hours a week permitted by their study visas.
Dr Klinkum said the authority recently identified 20 non-universities that compressed the 20-hours per week of contact time required for a full-time course into two or two-and-a-half-days.
He said in one or two cases there was a valid education reason for compressed delivery, but in the other cases the institutions were unable to provide any educational rationale for the arrangement and had changed it.
"We consider that type of compressed delivery to be inappropriate for international students. We're not convinced that it's educationally sound and also we believe that compressed delivery may be associated with arrangements whereby students can work beyond their work visa rights," he said.
Dr Klinkum said in general a foreign student on a full-time course requiring 20 hours a week of face-to-face contact should be at their tertiary institution most days.
"It's our expectation that an international student would be studying full-time, that's the purpose for which the visa was first issued, and so full-time study should look like the equivalent of four or five days of study per week so we would consider two-and-a-half days to be inappropriate."
Aspire2 is one of the biggest enrollers of foreign students and its chief executive, Clare Bradely, said she agreed two 10 hour teaching days were not good for teachers or learners.
However, Ms Bradley said eight hours of contact time per day was not compressed delivery and it was what most organisations were doing.
"Two-and-a-half, three days is what I think is probably pretty standard across the sector," she said.
"What's more important is the quality of the learning and how engaged the student is in the process."
RNZ has been told that compressing teaching into two or three days is done deliberately so that students can find jobs.
Ms Bradley said it was likely that courses were compressed into two or three days in order to make it easier for students to organise their time.
Paul Chalmers from Newton College of Business and Technology said the practice did help students find part-time work, but organisations should not be punished because some broke the rules and worked more than 20 hours a week.
"That's not something to do with the education provider, that should be sorted out by employing more Department of Labour inspectors," he said.
Mr Chalmers said eight-hour teaching days were appropriate because they helped prepare students for the working world.
"We teach courses over two-and-a-half days, from nine to five. We're a vocational provider and so we're mirroring the workplace environment where students are expected to go to when they leave the college."
The chairperson of ICL Graduate Business School, Ewen Mackenzie-Bowie, said the requirement for 20 hours of contact time per week was unfair because it only applied to foreign students in private institutions.
"If you go to a polytechnic to do a level 5 diploma in business, chances are you will only be studying for 12 to 15 hours a week, but if you go to a private training establishment, a private business school, you would have to be doing 20 hours a week. It's not a level playing field," he said.
Mr Mackenzie-Bowie said two days of teaching was inappropriate for an undergraduate course, but it is okay for postgraduate programmes where students might attend classes for six-hours a day over the weekend.