Students "completing" an 18-week course in just one day;
Event volunteers unwittingly being enrolled in courses and receiving qualifications;
Mass enrolments of students whose identity and domestic status could not be substantiated;
Teaching hours falling well short of funded levels;
Tutors being enrolled as students in courses they were teaching.
Those investigations, and another currently under way at Wairarapa private training establishment Taratahi Agricultural Training Centre, were the result of anonymous complaints lodged by students. The findings have prompted further reviews of institutions running courses with similar traits such as a high level of outsourcing of teaching; extremely high pass rates; and unexpected surges in enrolment numbers.
The expansion of the investigation did not necessarily indicate a widespread problem in the sector and it was important not to cast aspersions on the institutions involved - most of which have not been named - said Mr Joyce.
"The model of applying funding to these organisations has been around a long, long time so I'd be surprised if there was a widespread [problem]," he said. "But we've got to check."
Mr Joyce said it would be a "real concern" if practices highlighted in the completed investigations were widespread, and might indicate the system needed to be overhauled.
"That would be a sad day because effectively you'd be saying you can't trust people to do what they have been contracted to do," Mr Joyce said.
While he retained full confidence in the integrity of a funding system based on the number of equivalent fulltime students (or EFTs) on an institution's books, "obviously that is a qualified view until I have seen the outcomes of these next reviews".
He was confident the number of planned reviews would remain at 12 "as it stands".
The targeted reviews were a prudent response by TEC officials following the results of the first two investigations, he said.
"I think it's the right approach. They are thinking to themselves, 'what is going on here, we better go along and check some of these others and see if it is a wider issue or whether it is confined to the ones that we have identified so far'?"
Maori performing arts courses offered by a private training institution in Rotorua run by former Warriors board member Donna Grant and at Awanuiarangi are currently the subject of TEC investigations.
Mrs Grant, who has resigned her roles on the Warriors board and as Awanuiarangi's director of performing arts, is the subject of a Serious Fraud Office investigation.
An Official Information Act request submitted by the Herald to the TEC in September requesting documentation relating to the validity of attendance records at Awanuiarangi was rejected on Wednesday on the advice of the SFO as its release may have prejudiced its investigation.
The story so far
Sept 6: The Herald reveals the Warriors have been drawn into an investigation into the funding of a Maori tourism course.
Oct 2: The investigation confirms Warriors club members gained certificates after doing one day of an 18-week course. Course provider Te Whare Wananga o Awanuiarangi returns $5.9 million in course funding. Donna Grant, Awanuiarangi's director of performing arts, resigns from the wananga and is referred to the Serious Fraud Office and within days is replaced on the Warriors board.
Oct 11: A second investigation uncovers similar overpayments at the Western Institute of Technology in New Plymouth relating to Maori performing arts courses, resulting in a $3.7 million repayment.
Nov 21: Tertiary Education, Skills and Employment Minister Steven Joyce confirms 12 more "targeted" reviews are planned.