An anti-corruption watchdog says only four of 41 countries that signed an anti-bribery convention 16 years ago are actively investigating and prosecuting companies that bribe foreign officials to win contracts, or dodge taxes and local laws.

Transparency International, which annually assesses compliance with the OECD anti-bribery convention, said Thursday that Germany, Switzerland, the United Kingdom and the United States are the only countries considered to be actively enforcing the agreement.

The organization says six countries are classified as having moderate enforcement, nine have limited enforcement, and the remaining 20 "are doing little or nothing." Two could not be measured.

The worst category includes six of the Group of 20 global economic powers: Argentina, Japan, Russia, Mexico, Brazil, and Turkey.