Developed nations need to ensure they are not exporting corruption to emerging markets, according to Transparency International (TI).
The NGO cautioned corruption inhibits economic growth, and called on all nations to develop and improve measures to tackle unscrupulous behaviour.
The warning was made alongside the publication of the organisation's 20th Corruption Perceptions Index, the annual ranking of nations which measures opinion of how dishonest they are. More than two-thirds of countries on the list score less than 50, where a score of 0 means they are perceived to be highly corrupt.
José Ugaz, chairman of TI, said: “Countries at the bottom need to adopt radical anti-corruption measures in favour of their people. Countries at the top of the index should make sure they don’t export corrupt practices to underdeveloped countries.”
Denmark, New Zealand and Finland were the three countries perceived to most honest, where as Somalia, North Korea and Sudan were bottom of the list.
Turkey, Angola, China, Malawi and Rwanda all saw the biggest drops in their rankings, while Ivory Coast, Egypt, Saint Vincent and the Grenadines were seen as the most improved countries.
Corruption Perceptions Index 2014: Bottom 10 nations
1= North Korea
5. South Sudan