Australia's oldest university is investigating allegations that students took hidden cameras into an exam and uploaded the questions to a Chinese social media site.

On Thursday morning, parts of the University of Sydney's Introductory Microeconomics final exam were shared to Douyin — the original Chinese name and counterpart of TikTok.

Posts to the Chinese social media site indicated the students exposed the exam content using tiny cameras masked as shirt buttons.

A Douyin user shared a video of the University of Sydney exam room on Tuesday.

Students from the University of Sydney told the Daily Telegraph that the exam paper in the videos was the same one they sat.

The final exam was a high-stakes assessment, contributing 50 per cent of the final grade.

University vice chancellor and president Professor Mark Scott AO is investigating the scandal which has angered many students.

Many fear for the integrity of the test and whether it will be declared invalid. 

'If this is real then you all will have to re-sit the exam,' one person wrote on Reddit.

'How is everyone on equal grounds during the exam if the questions were leaked and certain individuals had an advantage over the rest?' another wrote.

'The structural, academic, institutional integrity has been compromised and we are aware how hard it is to come up (with) a reasonably equitable solution, but I think students have the right to ask for one.'

A spokeswoman for the University of Sydney said the social media posts were being investigated.

'We take any potential breach of academic integrity very seriously and anyone found to have engaged in this behaviour may face significant consequences under our disciplinary processes,' she said in a statement sent to Daily Mail.

'We take steps to ensure that the integrity of assessments is not compromised, including using different papers for replacement exams.

'We understand this incident may be upsetting for students sitting exams and support is available for anyone who needs it.'

A spokesperson at Australia's university regulator, the Tertiary Education Quality and Standards Agency (TEQSA), said: 'Incidents of this nature highlight the need for providers to continually review their assessment practices, evaluate the effectiveness of their controls, and adapt to an evolving risk environment.'