Inside Job, a searing assault on the banking industry and its role in the financial meltdown of 2008, has won the ultimate accolade from the film world: the Oscar for best documentary.

Director Charles Ferguson, who became a film-maker after making millions of dollars developing internet software, had lost out at the Oscars before, when his 2007 film about the Iraq war, No End in Sight, was nominated, but this time he had a happy ending.

Inside Job, which premiered at the Cannes film festival in 2010, traces the connections between government and financial institutions, as well as theoretically independent academics, showing how they combined to trigger excessive profit-taking and endanger the wider economy.

With this victory, Inside Job has outperformed an equally devastating attack on American politics, Michael Moore's Fahrenheit 9/11. Moore's movie wasn't even nominated.