An investigation is under way into possible cheating in a promotion process in the Revenue Commissioners.
The Revenue Commissioners has informed the Commission for Public Service Appointments that a number of people may have had accidental access to some of the test material.
Revenue is now investigating how the material was leaked and if it was on purpose or by mistake.
It said: "We are aware of a potential isolated incident of advance access to a psychometric test. Revenue is taking this matter very seriously.
"It does not however compromise the selection process because of the validation measures in place.
"These are a type of tests which are normally taken in an unsupervised online environment in any event."
Stage one of a competition for promotion to Executive Officer level involved the psychometric testing of verbal and numerical reasoning, which resulted in a shortlist for interview.
As a result of the test being seen in advance, candidates who perform successfully in the interview process will now have to undergo a verification exam before being promoted.
The CPSA, which is the regulatory body for public service appointments, has agreed to carry out an audit of the competition process once it is complete.