An anti-corruption campaign group has urged governments in the West to help Africa recover part of the wealth lost through corruption.
The group says corruption is harming Africa's development
Transparency International made the appeal in the Kenyan capital, Nairobi.
The group estimated the amount of illegally appropriated money invested outside Africa to be $140bn (£80.4bn).
It called on Western governments to change their banking laws to make it easier for illegally acquired wealth to be repatriated to Africa.
Transparency International (TI) which leads a campaign against corruption worldwide, says the phenomenon is seriously undermining Africa's fragile democracies and hindering efforts to achieve sustainable development.
Representatives of TI from seven African countries, including Zambia, Zimbabwe and Uganda, said that if Africa was to reverse the trend, it was imperative that African governments demonstrated the political will to fight corruption in a meaningful way.
But the organisation says without active co-operation from western governments the process could take 100 years to complete.
Although difficult to quantify, analysts estimate Africa has lost more than $140bn due to corruption both by its own governments and Western companies in the post-colonial period.
In a declaration adopted at their meeting in Kenya, Transparency International representatives said it was not only illegal, but blatantly immoral that so much wealth stolen from Africa was allowed to circulate freely in the world's wealthiest nations.
Last year, a United Nations treaty against corruption came into effect. It enables illegally acquired assets to be seized and eliminates banking secrecy protection for those under investigation.
The measures to tackle corruption are there, say campaigners. What is needed to make it happen is more political will.