Every community has regulations to be obeyed and every community has people to make sure this will happen. A working community is by no means an exception. When a person agrees to work in an organisation, religiously the person is obliged to observe and follow the regulations of that organisation.
If a person does not follow the regulations in the organisation and commits fraud, then this will be religiously wrong and will also bring disruption and injustice to the system.
With the above view, the so called "whistle blower", as you defined it, is doing nothing but upholding what is right and just by fighting against wrong and injustice.
It is reported that the Prophet (sws) has said: “Whoever among you sees (something that is generally known as) a bad (munkar) evil, he should change it with his hand (by taking action); if he cannot, then with his tongue (by speaking out); if he cannot, then with his heart (by hating it and feeling that it is wrong), and that is the weakest of faith.” (Muslim 70).