Students in Dundalk Institute of Technology have been told they must all resit an exam after a test paper had been "compromised."
Around 20 final year agriculture pupils have been affected, and the college has launched an investigation.
The college says that those who will need to resit the exam have been contacted.
According to reports, a number of those taking the exam had gained access to the questions beforehand.
The exam is due to be resit today with those unable to attend retaking it in August.