Governments in Africa's biggest economies - Kenya, Nigeria and South Africa - have during recent years weakened the independence and powers of anti-corruption agencies. In all three, the leaders of anti-corruption efforts - John Githongo, Nuhu Ribadu and Leonard McCarthy - have been removed. Githongo and McCarthy have gone overseas to new jobs - Githongo to Oxford University and McCarthy to lead the World Bank's anti-graft team - while Ribadu is on hastily-arranged study leave. Complaints mount in other countries: Ghanaians say their Human Rights and Administrative Justice Commission is under-funded and impotent; Tanzanians ask why President Kikwete took two years to act on a damning audit of Central Bank transactions and sack the Governor. Yet progress by better resourced Western anti-graft investigators is not that impressive. As reported last week, four years' work by American, British and French investigators into corrupt payments linked to Nigeria's US$10 billion gas export plant have revealed little more than that a British lawyer - yet to face trial - handled $180 mn. of 'consultancy payments'. British investigations into corrupt payments on BAE Systems contracts in Tanzania and South Africa move painfully slowly. There is a growing sense that international vested interests - political and corporate - are blocking serious efforts to prosecute the offenders.