The Fighter, David O Russell's Oscar-nominated true story of 90s boxer Micky Ward, played by Mark Wahlberg, is about a guy who slugs his way up from the tough streets of Lowell, Massachusetts. He has a troubled relationship with his half-brother and trainer Dicky Eklund (Christian Bale), a former boxer who is now addicted to crack but who finally appears to confront his demons, at least partly as a result of a television documentary being made about him as the movie begins: we see the camera crew following Micky and Dicky around.
This documentary really did exist. Entitled High on Crack Street: Lost Lives in Lowell and directed by Maryann DeLeo and Richard Farrell, it was transmitted on Us TV in 1995 and is now available for free on the web.
Watching High on Crack Street