What is a 'reasonable suspicion'?
A reasonable suspicion is the threshold set by the Commissioner's Directions and Guidelines for the reporting obligations of public officers, public authorities and inquiry agencies.
Those Directions and Guidelines define suspicion as something short of knowledge or belief. You may suspect a set of circumstances or state of events without either knowing the circumstances or event have occurred, or without having any belief that they have occurred. You merely suspect they might have occurred. It is a subjective state of mind that you must hold yourself.
However, the obligation that a public officer has to report conduct to the Office for Public Integrity (OPI) requires a suspicion be reasonable. For a suspicion to be reasonable, there needs to be a rational basis for the suspicion. Whether or not this is the case will depend on the facts upon which the suspicion is based, and the plausibility of those facts
For example, if you saw an unauthorised person access the petty cash and it later became known that there was $100 missing, you might have grounds to reasonably suspect that that person took the money. However, if ten unauthorised people accessed the petty cash, it might not be reasonable for you to suspect any particular individual without further information.