Learn the meaning and usage of the word investigation from various sources, such as dictionaries, thesaurus, and idioms. Find out the synonyms, translations, and related terms of investigation . 1600. “ Investigation ” includes all the proceedings under “the Code of Criminal Procedure, 1973” for the collection of evidence conducted by a Police officer or by any person (other than a Magistrate) who is authorized by a Magistrate. (Section 2(h) of the Criminal Procedure Code). Re- investigation is a process of investigation denovo and CrPC is silent in relation to the process of re- investigation . Re- investigation without permission is prohibited but further investigation is permissible. Investigation definition: the act or process of investigating or the condition of being investigated.. See examples of INVESTIGATION used in a sentence.