Johannesburg — South Africa has shown unfavourable governance performance since 2006, the 2012 Mo Ibrahim Index of African Governance said in a summary report on its website.

Over the past six years, it found that Egypt, Kenya, Nigeria and South Africa had declined in two categories -- safety and rule of law, and participation and human rights.

"Each of these four countries deteriorated the most in the participation sub-category, which assesses the extent to which citizens have the freedom to participate in the political process."

South Africa and Kenya had also registered declines in sustainable economic opportunity.

The London-based foundation publishes the index, ranking 52 African countries according to 88 indicators grouped under safety and the rule of law, participation and human rights, sustainable economic opportunity and human development.

There has been no change in its top five this year -- with Mauritius topping the index with a score of 83 out of 100, ahead of Cape Verde with 78, Botswana 77, Seychelles 73 and South Africa 71.

Somalia remained at the bottom with a score of seven, behind Democratic Republic of Congo, Chad and Eritrea with 33.