The lower ranking, which places South Africa on par with its Brics counterpart Brazil, did not surprise industry commentators canvassed by Engineering News Online, who said that the ranking was an accurate reflection of increased negative perceptions about the prevalence of corruption in the country.
The CPI, released on Wednesday, ranked South Africa 69 out of 176 countries, with a score of 43, which is also the global average.
Last year, the index ranked countries out of a score of ten. South Africa scored 4.1 out of 10 and ranked 64 out of 183 countries. In the prior year, South Africa ranked 54 out of 178 countries.
The index rated countries according to perceptions surrounding corruption in each country, with scores from the "highly corrupt" at 0, to the "very clean" at 100.
BDO South Africa manager Pierre Kilian told Engineering News Online that the "message" South Africa was transmitting to the world in a variety of ways, was that corruption was condoned and that public funds were misused, which was influencing people's perception.
He pointed to media headlines over the past year reacting to expelled African Natioanl Congress Youth League leader Julius Malema's tender fraud case, the ongoing arms deal saga, the bailout of State-owned South African Airways and the reshuffling of Cabinet Ministers, besides others.
South Africa ranked ninth from the top in Africa, but when compared with the ranking of neighbouring Botswana, South Africa was a long way off from improving how corrupt it was perceived as.
Botswana, with a ranking of 30 and a score of 65, was perceived as the least corrupt country in Africa. Kilian noted that Botswana had adopted an approach of zero tolerance with regards to corruption and backed this up with action.
Cape Verde, Mauritius, Rwanda, Seychelles, Namibia, Ghana and Lesotho all ranked ahead of South Africa.
South Africa has been on a gradual slide downhill over the past few years and would most likely continue to decline if a zero tolerance approach was not adopted soon, he said.
Corruption Watch executive director David Lewis agreed, saying that investors shy away from corrupt environments and customers would seek service providers elsewhere.
While there have been indications of a more serious approach from government, conflicting messages were being sent.
Kilian and Lewis said that strong policy and legislation were in place to efficiently deal with corruption, but that enforcement lacked.
Corruption Watch, which received about 100 reports of corruption a month and more than three reports a day, believed that business and the public should intensify their involvement in tackling the challenge.
Transparency International chairperson Huguette Labelle added: "Governments need to integrate anticorruption actions into all public decision-making. Priorities include better rules on lobbying and political financing, making public spending and contracting more transparent and making public bodies more accountable to people."
Meanwhile, South Africa remained ahead of three of its Brics counterparts, namely China, with a ranking of 80; Russia, which ranked 133; and India at 94, but tied with Brazil, which jumped to 69, from a ranking of 75 last year.
The index pointed out that 90% of the countries in sub-Saharan Africa and 78% of the countries in the Middle East and North Africa scored below 50.
Globally, 70% of the countries scored below 50, with the European Union and Western Europe, the Americas, Asia Pacific, and Eastern Europe and Central Asia recording that 23%, 66%, 68% and 95% of each region' countries scored below the halfway mark.
Denmark, Finland and New Zealand maintained their top three positions, with scores of 90 each, while Sweden and Singapore again placed fourth and fifth with scores of 88 and 87 respectively.
Myanmar and Sudan recorded the fifth- and fourth-lowest scores, with 15 and 13 respectively, while Afghanistan, North Korea and Somalia once again were seen as the most corrupt with scores of 8.
