Two thirds of the 176 countries ranked in Transparency Internationals index on corruption perceptions scored below 50 this year on a scale from 0 (perceived to be highly corrupt) to 100 (seen as very clean), the non-profit organization said.
Denmark, Finland and New Zealand all tied as the least corrupt countries in the world, with 90 points, while Somalia, North Korea and Afghanistan were perceived as the most corrupt with 8 points, the Transparency International Corruption Perceptions Index 2012 showed.
While no country has a perfect score, the majority of countries score below 50, indicating a serious corruption problem, Huguette Labelle, Transparency International chair, said.
Corruption in all its facets thrives on secrecy and on the perception by the corrupt that they are somehow above the law. We must ensure that there are real consequences to corruption.
By geographical region, Eastern Europe and central Asia was perceived as the most corrupt, with 95% of countries scoring below 50. Georgia - where a drastic reform of police forces which has seen thousands of officers replaced was carried out relatively recently - was ranked as the least corrupt with Turkmenistan and Uzbekistan perceived as the most corrupt.
Sub-Saharan Africa was next, with 90% of countries scoring below 50; the least corrupt was Botswana and the most corrupt, Somalia.
In the Middle East and North Africa, 78% scored under 50, with Qatar and the United Arab Emirates the least corrupt and Iraq the most.
Asia Pacific followed, with 68% of countries scoring below 50. New Zealand was the least corrupt in the region while Afghanistan and North Korea, the most corrupt.
It was followed by the Americas, with 66% scoring below 50; Canada was the least corrupt while Haiti and Venezuela, the most.
The region that was perceived the least corrupt overall was the European Union and Western Europe, where 23% of the countries scored below 50. The least corrupt countries were Denmark and Finland and the most corrupt was perceived to be Greece, which scored 36, on a par with emerging countries such as Colombia, India, Moldova or Mongolia.