Hands Over the City

In 1963 Francesco Rosi, an Italian film maker, released Hands Over the City, starring Rod Steiger speaking Italian. It's the story of municipal corruption in the the land development industry in Naples. In 1992, Rosi released Neapolitan Diary, a documentary about going back to Naples and confronting the issues of Camorra control of that city.
These movies make explicit the role between politics and corruption.
The 1992 film was shot just weeks after two Italian judges, Giovanni Falcone and Paolo Borselino were murdered by mafioso in Palermo Sicily. The tone of the Diary is angry and defiant: a kind of we're mad as hell and we're not going to take it anymore. It is also part travelogue from the heights of Mount Vesuvius through old Naples, and among the hideous modern Camorra-built suburbs.
It is a superb primer for anyone who wants to understand just how money-laundering, construction, land development and mobs work (for themselves) and don't work (for everyone else.)
Both films and some other features were released on the Criterion Collection as DVD's, get them from your library, get them from your favourite movie rental spot, but get them.