Angola and Zimbabwe are the two Southern African countries that faired the worst in Transparency International's (TI) Corruption Perception Index (CPI) for 2003.
The CPI charts the level of corruption in 133 countries and ranks them according to a CPI score based on perceptions of the degree of corruption, ranging from 10 (highly clean) to 0 (highly corrupt), by business people, academics and risk analysts.
Angola and Zimbabwe faired worst in the rankings, with CPI scores of 1.8 and 2.3 respectively, followed by Zambia (2.5), Madagascar (2.6), Mozambique (2.7) and Malawi (2.8).
Botswana was the best-performing country in the region, with a CPI score of 5.7 out of 10. Namibia followed with a score of 4.7, while South Africa scored 4.4.
Globally, TI said, "seven out of 10 countries score less than 5 out of a clean score of 10, while five out of 10 developing countries score less than 3 out of 10".
Angola joined countries such as Nigeria and Indonesia, where "corruption is perceived to be pervasive", said the report, which was released on Tuesday.
Zimbabwe joined countries such as Argentina and Israel as "noteworthy examples of a worsening" situation with regard to corruption.
The 2003 CPI "demonstrates that it is not only poor countries where corruption thrives," said Laurence Cockcroft, a member of TI's international board, in a statement. "Levels of corruption are worryingly high in European countries such as Greece and Italy, and in potentially wealthy oil-rich countries such as ... Angola."
"To turn around this situation, so that ordinary people share in the oil wealth of their country, TI is campaigning, along with other NGOs, for international oil companies to publish what they pay to governments and state oil companies. This will enable citizens and civil society organisations in countries such as Nigeria, Angola, Iraq, Indonesia and Kazakhstan to have a clearer picture of state revenues," said Cockcroft.
Citizens of countries like Angola could then "call their governments to account where the state budget is not used to improve scarce public resources, but instead disappears on expensive vanity projects or into the secret offshore bank accounts of politicians and public officials".