South Africa is launching a national survey to asses how bad corruption affects its citizens, government and business.

The government is undertaking the project together with the United Nations Office for Drug Control and Crime Prevention, to provide a baseline for future work against corruption.

One aim, said Geraldine Fraser Moleketi, South Africa's minister for public service and administration, was to correct what she saw as overestimates on the part of foreign firms of how bad corruption is in South Africa.

"Many investors have been hoodwinked by skewed perception of levels of corruption in our country, and also in the rest of our region," she said.

"The new data will give policy makers a clearer picture of the extent of business-related corruption and crimes - including bribery, fraud, extortion and intimidation - and how they impact on productivity and investment."

Broader picture

The survey, which will cost 4m rand ($365,000, �250,000), is part of a global effort undertaken by the World Bank to chart the extent of corruption around the world.

The thinking behind it is that foreign investment is badly needed to encourage development, but is put off by the perception of corruption.

In South Africa, foreign direct investment amounts to just 1% of gross domestic product.

The survey will see 1,000 people interviewed in random telephone interviews from 23 April onwards, with a final report due in June.