in·ves·ti·ga·tive 
(ĭn-vĕstĭ-gā′tĭv)
(ĭn-vĕstĭ-gā′tĭv)adj.
1. Of or relating to investigation: investigative methods.
2. Characterized by or engaged in investigation; specializing in uncovering and reporting hidden information: investigative journalism.