The PhD project studies one of the most effective ways to detect corruption - whistleblowing. Corruption is difficult to detect because there are often weak incentives for those with insight into corruption to alert law enforcement or the media, partly because corruption often does not have a clear target. Bystanders who witness or suspect wrongdoing take great risks in blowing the whistle, with both formal and informal reprisals against whistleblowers common. Work culture is often also a barrier, with dominant workplace norms punishing those who 'blow the whistle' and show 'disloyalty' to management and colleagues. In addition, there are often no clear rules and procedures for reporting irregularities and misconduct. The project takes a holistic approach to the whistleblowing issue and analyzes the historical development of the concept, its spread and not least the legal significance of the concept in international and foreign law. Furthermore, Swedish law is studied in the light of the whistleblowing concept. The study necessarily goes beyond a study of accepted legal concepts such as labor law's right to criticize or state law's freedom of communication. The thesis thus makes a different cut in the law and illuminates it from a new perspective and exposes new issues that are relevant in our time.