It is understood as many as 10,000 assignments, allegedly written by ghost writers, could have been submitted to institutions around New Zealand. Authorities acted after two people came forward making allegations that the website was providing assignments for between $300 and $500.
The matter is back before the High Court in September.
Police have searched the offices of Ateama Ltd and seized a number of computers and other material.
Ateama Ltd was contacted for comment. A staff member said someone would phone back to answer questions. That had not happened by tonight.
NZQA chief executive Dr Karen Poutasi said authorities are analysing the large amount of material seized by police.
"Today's Court proceedings are part of the strong NZQA action taken in response to allegations of cheating and assessment fraud. Where there is evidence of illegal activity under the Education Act, it is likely further legal action will be taken."
A working party has been set up by NZQA and Universities NZ - an organisation that represents the country's eight universities.
The working party will look at the extent and impact of any cheating that has gone on. It will also look at ways it can stop cheating services in future.
Dr Poutasi told APNZ the working party had already had two meetings.
She said there are software packages available to detect cheating and plagiarism, and a good lecturer will be able to tell if a student has used a cheating service.
Asked for an example, she said a lecturer could become suspicious if a student is unable to talk about their assignment.
Dr Poutasi said the working group was not just confined to Assignments 4U but she was not aware of other websites offering cheating services for money in New Zealand.
She said she could not say what will happen to students who have used cheating websites.
"I can't comment because we don't know the magnitude of the issues."
The office of Tertiary Education Minister Steven Joyce was contacted for comment but did not return phone calls.
