The anti-corruption watchdog group, Transparency International, has ranked Bangladesh and Haiti as the world's most corrupt countries in its annual report.
The Transparency International corruption index finds that rampant corruption persists in 60 countries out of 146 surveyed.
According to the index, corruption is perceived to be most acute in Bangladesh, Haiti, Nigeria, Chad, Burma, Azerbaijan and Paraguay.
Finland tops the list of the least corrupt countries, followed by New Zealand, Denmark, Iceland, Singapore, Sweden and Switzerland. The United States is tied with Belgium and Ireland in 17th place on the index.
The chairman of Transparency International, Peter Eigen, says levels of corruption are often especially high in oil-rich countries. He said there is particular concern that bribery will surge in Iraq as it restores oil production and undertakes post-war reconstruction projects.
"The risk in Iraq is clearly that this will not be done as conscientiously and rigorously now, as in normal times," he said. "Whenever there is a rush, there is a push, and in particular when petroleum is involved, then the danger of corruption is immense. Therefore, our effort is to warn the authorities who are now calling the shots to make sure that corruption does not become too deeply ingrained in Iraq."
Transparency International estimates that $400 billion a year are lost to bribery in government contracting. As part of its campaign against corruption, the group is calling on Western governments to make oil companies publish what they spend in fees, royalties and other payments to governments and state oil companies.
