More than 160 final year law students have to re-sit their exams at the University of Tasmania.
The ABC reports some fifth-year students cheated in a recent online test on criminal and civil procedure.
The university will not say how many students are involved or if the culprits have been identified.
The ABC reports the entire class is being punished and grades they have already earned this semester are to be wiped from their academic records.
Students will also have to sit additional assessments including an in-class test and a formal exam.
"Cheating on an exam for somebody who wants to be a lawyer is a serious issue," said Tasmanian Law Society spokesman Daniel Zeeman.
The ABC reports the university student union is having discussions with the law faculty about how to punish the cheaters and not the entire class.