The Australian National University (ANU) reversed its decision to deduct grades from around 300 computer science students because of suspected plagiarism within the cohort.

In an email to members of a third-year algorithms class on Tuesday night, the directors of the School of Computer Science apologised "for the confusion and any distress" caused by a message the course convener sent to students on Monday regarding their grades.

In that message on the class' Piazza site, the course convener suggested students would all lose 30 per cent of the final grade as a "penalty" for apparent mass-plagiarism.

"We recognise that the message lacked precision and should have been clearer," the School of Computer Science said in its email.

"It is our intention to learn from this and do better in future.

"We also apologise for creating the impression that we have administered a group punishment.

"We have not done so, and will not be doing so."

The school also clarified the original situation, saying that it had noticed the marks for the class's final project to be "unusually skewed".

To compensate, the university applied what it called "standard measures of adjustment" to the entire class – effectively scaling down everybody's results.

"As a separate issue, there was also evidence noted of wide-spread academic misconduct for the assignment," the school said.

"Nonetheless, in order to alleviate any possible suspicion of the connection between routine mark adjustments and the detection of wide-spread academic misconduct, we are reinstating the original marks for this assessment for all students."

President of the ANU Computer Science Students’ Association, Felix Friedlander – who contacted the school following complaints about its initial messaging – welcomed the university's decision.

"This incident has highlighted how in the face of rampant academic misconduct, even routine measures like scaling can become a punishment on honest students, and how important it is that suspicions of academic misconduct are investigated – fairly," he said.

"For now, though, this seems like a positive outcome for the students in that course, and I appreciate the school resolving this matter promptly, even so close to the end-of-year shutdown."