Students in a third-year course on algorithms at the Australian National University (ANU) were surprised to learn they would all lose 30 per cent of their grade on Monday due to suspected plagiarism within the cohort.

After discovering students outsourcing their final assignment online and not being able to track down the culprits, the university decided to dock the entire class.

The ANU said it "takes academic integrity seriously" and that other course marks would be re-scaled.

"The university is aware of a situation surrounding alleged academic misconduct for an assessment for one course in the ANU College of Engineering and Computer Science," a spokesperson said in a statement.

"Because this assessment has been compromised, to maintain the course’s academic integrity other assessments have been re-scaled accordingly to the benefit of all students, and students are able to score 100 in total for the course."

In question was the subject’s major assignment: a project to propose, design, and deliver a program using C, C++, Java, Python, or Haskell that was due in early November.

The university discovered what appeared to be students trying to outsource the assignment online via online learning platforms but could not determine who was behind the attempted plagiarism.

On Monday, course convener Dr Hanna Kurniawati informed her class of about 300 students that they would all be penalised due to the “massive academic misconduct reports”.

"Please don't complain to teaching staff about this penalty, rather you should complain to your colleagues who were trying to outsource [the assignment],” Dr Kurniawati told her students.

"Though, we're nice enough to put the minimum of [the assignment] mark to be zero (ie. none get negative mark)."

Students were naturally frustrated that everyone was being punished for the actions of a few with one writing on social media “imagine the police sentencing everyone to death because they couldn’t find the murderer”.

President of the ANU Computer Science Students’ Association, Felix Friedlander, wrote to the university saying the decision to penalise all course students was "unacceptable".

"I understand that allowing the plagarised assignments to receive full marks feels wrong for a variety of reasons – in short, people may have passed a course without learning or demonstrating an understanding of some of the associated content.

"However, by penalising uniformly, you have introduced the opposite scanario – students who have learned and demonstrated an understanding of the course, to what would have otherwise been an acceptable level, may not pass.

"The announcement of such a change so late in the year — after grade release, even — as well as your attempt to direct enmity within the student cohort, only adds to the stress this announcement brings to students in what has already been an incredibly stressful year."

The ANU’s academic misconduct rules are found in Commonwealth legislation.

Collusion is included in the rules, but otherwise tend to focus on the behaviour of “a student” and penalties towards individuals, not whole classes, following a lengthy review process.