Company informer

• Person with inside information making public some illicit activity
• Employee who calls out bad practices, say
• One discloses having broken elbow in Canadian ski resort

Wikipedia Word definitions in Wikipedia
A whistleblower is a person who exposes misconduct occurring within an organization. Whistleblower may also refer to: Whistleblower (magazine) , a monthly news magazine Whistleblower (TV series) , a television drama Whistleblower (The Office) , an episode ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
also whistle-blower , 1963 in the figurative sense, American English, from whistle (n.) as something sounded in an alert + agent noun from blow (v.1).

WordNet Word definitions in WordNet
n. an informant who exposes wrongdoing within an organization in the hope of stopping it; "the law gives little protection to whistleblowers who feel the public has a right to know what is going on"; "the whistleblower was fired for exposing the conditions ...