Some of the strongest critics of "visa factory" schools are the senior executives of rival schools, who believe the rorts are undermining their own businesses and the reputation of the whole international educationindustry. These are the main points they see as weaknesses in the current system.
Heads of competing institutions say Massey University's purge last year of about 50 students with false qualifications was predictable because so many schools accept foreign students into lucrative Diploma of Business courses, even though their English is blatantly below the standard required.
AIS St Helens academic director Dr Mike Roberts says entry level is usually between 5 and 6 on the International English Language Testing System (IELTS) but some students have been admitted with scores as low as 3.5.
"We would certainly not want those students to go into our courses with that level of English. They would fail everything - they wouldn't understand anything.
But somehow these students get offered a place in this programme."
Roberts and Languages International chief executive Darren Conway say they have repeatedly sent written examples of this to NZQA but get no action. Schools typically claim they will bring the students up to speed but no one checks whether this happens and the Massey experience suggests it seldom does.
Roberts says many schools rely too heavily on agents, who recruit their students for commission rates of up to 40 or 50 per cent of the student's fee.
"There are some private institutions that are really desperate for students and are paying huge commission rates. If you pay 40 per cent of your fees just for an introduction, what have you got left to run your programme on?"
School directors say some agents have high standards but others are less trustworthy. One describes meeting an agent who offered an extra 50 students in exchange for supplying all their course tests in advance.
"(He said) that will assist the students in passing. One would imagine it would. I said, 'No thank you, we don't operate like that'. So we haven't got those 50 students. I do know that they have gone elsewhere."
One former principal says agents exercise huge power in the industry, which many schools find hard to resist.
"If (students) didn't pass they would ring up and say we're not going to give you any more students unless you pass these." He says he always refused "otherwise word gets round and you're history".
Schools blame agents as much as students for "waka jumping", saying it's common practice for them to split the agent's commission when the student switches to a new school.
Most say the trick has become less popular since the Immigration Service stopped automatically transferring the student's visa to the new school.
However, others say it persists as a merry-go-round in which agents regularly swap students between schools to keep up their incomes in a falling market.
International Travel College director Karen Houston says reports of widespread cheating raise questions about New Zealand's reliance on internal assessment for most qualifications.
She says many overseas organisations demand closed-book exams instead. "Those qualifications have high value in the international community because everybody knows that you can't fiddle those."
She doubts official results showing 100 per cent pass rates in some organisations.
"I've been in this business a really long time now and I've never witnessed that myself. There's always students who drop out, there's always students who don't make the grade. It strikes me that you're either making it too easy or there's something else going on."
Conway agrees and believes the system needs university-style identity checks to prove that the person submitting the work actually did it.
He also thinks NZQA should send in mystery shoppers to test what schools do, rather than what they tell reviewers and auditors.
Several staff say spot checks with no advance warning are the only way to catch rogue operators. One says if reviewers went through each school's test results - which they are obliged to keep for two years - they would find widespread evidence of identical answers.
Not all schools are critical of NZQA. New Zealand Career College chief executive Feroz Ali says the agency is doing a good job, especially through its move to simplify the huge number of qualifications now available.
He predicts this overhaul will force every school to justify why it teaches each vocational course and whether it genuinely leads to a job, which in turn will weed out the suspect schools. NZQA deputy chief executive quality asurance Tim Fowler says most of the 700-plus private training establishments (PTEs) in New Zealand work well for their students but there are exceptions.
The authority established a confidential hotline 0800 INFORM (0800 46 36 76) through Crimestoppers in September for anyone to report fraud or other illegal activity.
Asked if NZQA does enough active investigation of suspect schools, he says site visits are not the only way to gather information. Staff use a range of methods, including co-operation with Immigration, but need firm evidence to take action.