("vilepuhuja") = informant

olemus
väärnähtuste avalikustaja
Wiktionary:
one who reports a problem or violation to the authorities; especially, an employee or former employee who reports a violation by an employer

ülevaateid
https://en.wikipedia.org/wiki/Whistleblower
https://www.unodc.org/documents/treaties/UNCAC/COSP/session5/SpecialEvents/2013_11_24_SlaganaTashevaTransparencyInternational.pdf
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/415175/bis-15-200-whistleblowing-guidance-for-employers-and-code-of-practice.pdf
https://www.ilo.org/wcmsp5/groups/public/---ed_dialogue/---sector/documents/publication/wcms_718048.pdf

näiteid
https://en.wikipedia.org/wiki/List_of_whistleblowers
https://www.employmentlawgroup.com/timeline-us-whistleblowing/
https://www.thewrap.com/9-whistleblowers-who-changed-the-course-of-history/