Many investigative documentaries set out to challenge or critique powerful institutions, individuals, or organisations. Their aim is to inform the public about matters that are often not widely known, and to hold those in power accountable for their actions. Investigative documentaries can be seen as a form of public interest journalism, and they can play an important role in shedding light on corruption, injustice and other wrongdoings.
Some well-known examples of investigative documentaries include Michael Moore's "Roger & Me" (1989), which looked at the impact of General Motors' plant closures on Flint, Michigan; Errol Morris's "The Thin Blue Line" (1988), which led to the re-trial and acquittal of a man who had been wrongfully convicted of murder; and Robert Greenwald's "Walmart: The High Cost of Low Price" (2005), which exposed the exploitative labour practices of the world's largest retailer.
Investigative documentaries can be produced by film studios or independent filmmakers, and they can be distributed in a variety of ways. Some are broadcast on television channels; others are released theatrically; and still others are made available online. Investigative documentaries have become increasingly popular in recent years, as audiences become more interested in documentaries that offer in-depth and critical perspectives on important issues.