PARK CITY ? After tackling the collapse of Enron and the torture of detainees in Afghanistan, film-maker Alex Gibney is shining a light on corruption in US politics in his latest film.

Gibney, who won an Oscar in 2008 for his account of how an Afghan taxi driver died in US custody in the documentary "Taxi to the Dark Side", has now turned his camera on the life and crimes of jailed lobbyist Jack Abramoff.

The documentary ? "Casino Jack and the United States of Money" ? is vying for honors at the Sundance Film Festival, where it is screening in competition.

Abramoff was a top Washington lobbyist during the Republican rise to power in Congress in the 1990s, and expanded his influence with George W. Bush's election to the White House in 2000.

He was jailed for nearly six years in 2006 after admitting corruption, fraud and tax evasion charges, and according to Gibney is emblematic of the new breed of "political terrorism" which perverts government.

"In many ways Abramoff is both deadly serious and deeply ridiculous," Gibney told Agence France-Presse. "And some of these things were just too outrageous and funny to be treated in any kind of a sober way. You had to laugh and cry at the same time. I like to say that it's a comedy, but the joke is on us."

Gibney said he hoped his film would open the eyes of Americans to the world of political financing.

"When you go behind the scenes in a sausage factory, it's pretty scary," he said. "This film takes you back into the kitchen and it's not so pretty."

"In which other country in the world, except countries deeply corrupt like Indonesia or Nigeria, is money so openly displayed to buy and sell political leaders? It's just shocking," Gibney said.

The film-maker believes the rise of corruption in American politics can be traced back to the election of Ronald Reagan in 1980, an event which coincided with a "fundamental shift" of values.

"We've adopted a value that says that money is the ultimate value. And in that way you measure everything," Gibney said. "You measure success, you measure failure and now we measure our political system that way."

"In the United States, the corruption is legal. That's the terrifying thing. We have reached the idea that it's good. Campaign finance is a system which legalizes bribery. How can we be comfortable with that?"

"Abramoff and these guys are like political terrorists. They don't use guns but they want to destroy the government. Because they fundamentally don't believe in the values of government.

"They believe in a kind of libertarian law of the jungle world."

Gibney believes a system of tightly regulated public campaign finance is essential for the situation to improve.

"It has to happen. If it doesn't happen, we are finished," he said.

In that regard, Abramoff performed a vital public service, Gibney said.

"Jack, I think, gave us all a big service," he says. "He showed us in spectacular fashion just how bad it is. For that, we should really be thankful."