muckraker       
noun [ C ]  disapproving uk/ˈmʌkˌreɪ.kər/ us/ˈmʌkˌreɪ.kɚ/
 (尤指新闻机构内)搜集并揭露丑闻的人
a person, especially one in a news organization, who tries to find out unpleasant information about people or organizations in order to make it public
  He made a name for himself as a celebrity muckraker in this relatively quiet little city. 在这个相对安静的小城市,他以揭发他人丑闻而出名。 
 Muckrakers aren't likely to dredge secrets from his past.  那些专门揭发丑闻的人不太可能从他的过去中挖掘出秘密。 
 See: muckraking
 - More examples
 - He's a professional muckraker who makes a decent living going through rubbish.
 - She has a reputation as one of journalism's most thorough muckrakers.
 - An opportunistic muckraker may have come across the document illicitly.