"Investigative journalism is a type of reporting in which reporters deeply investigate a topic of interest, often involving crime, political corruption, or some other scandal.
De Burgh (2000) states that: "An investigative journalist is a man or woman whose profession it is to discover the truth and to identify lapses from it in whatever media may be available. The act of doing this generally is called investigative journalism and is distinct from apparently similar work done by police, lawyers, auditors and regulatory bodies in that it is not limited as to target, not legally founded and closely connected to publicity".
An investigative journalist may spend a considerable period researching and preparing a report, sometimes months or years, whereas a typical daily or weekly news reporter writes items concerning immediately available news. Most investigative journalism is done by newspapers, wire services and freelance journalists. An investigative journalist's final report may take the form of an exposé." Source: Wikipedia