Thread: whistleblower

The most precise translation is осведомитель?

Yes, it's precise enough translation. Another good translation is информатор.

The process of whistle blowing how is translated?

стукачество, доносительство

Oxford dictionary: whistle-blower (used especially in newspapers)a person who informs people in authority or the public that the company they work for is doing something wrong or illegal

I am not sure the exact single noun exists. Доносить (сообщить) о нарушениях expresses the idea.

стукач is usually associated with prison contexts (it's prison slang), one who provides information on other prisoners to prison authorities

доноситель is a word popular in the USSR context (one who secretly tells the police about someone doing something or tells their bosses about their colleagues, etc.)

осведомитель - very often it's a police informant

информатор - one who provides information

"добыча и передача разведывательной информации" - is one aspect of wider activity called "шпионаж", normally they use it.
If you need to be more specific, then you have to be very verbose ("добыча и передача разведывательной информации"), or in colloquial talk - "стукачество".

If the person is treated positively, and s/he has disclosed some evil facts, s/he can be called разоблачитель.