Berlin - New Zealand and Denmark topped the list of Transparency International's 2017 Corruption Perceptions Index while South Africa ranked at 71.
Transparency ranks 180 countries and territories by perceived levels of public sector corruption where zero is highly corrupt and 100 is very clean. It relies upon 13 expert data sources, including assessments from the World Bank, the African Development Bank and the World Economic Forum, to determine levels of bribery, diversion of public funds, use of public office for private gain and other issues of corruption.
The watchdog group said on Wednesday that its 2017 Corruption Perceptions Index "reveals some disturbing information" with corruption continuing to be a global problem and the majority of countries moving too slowly in their efforts to combat it.
"Despite attempts to combat corruption around the world, the majority of countries are moving too slowly in their efforts," the Berlin-based organisation said. "While stemming the tide against corruption takes time, in the last six years many countries have still made little to no progress."
The best performing region was Western Europe with an average score of 66, while the worst performing region was sub-Saharan Africa with an average of 32, followed closely by Eastern Europe and Central Asia with an average of 34. The global average was 43.
New Zealand and Denmark topped the list at 89 and 88, respectively, with Somalia at the bottom with a nine, then South Sudan with 12, Syria with 14 and Afghanistan with 15.
South Africa ranked 71 with a score of 43.
Britain was cited as one of the most improved over the past six years, raising its score by eight points since 2012 to 82, placing it in this year's rankings one point above Germany and tied with the Netherlands, Luxembourg and Canada. The United States was tied in 16th place, along with Austria and Belgium, with a score of 75.
Other large increases since 2012 were seen in Greece, which rose 12 points to a score of 48 to put it in 59th place this year, Belarus which rose 13 points for a score of 44 and 68th place, and Myanmar which rose 15 points for a score of 30 and 130th place.
Australia fell eight points since 2012 and is now ranked in 13th place with 77 points, tied with Hong Kong and Iceland. Other large declines since 2012 included Syria, which dropped 12 points, Bahrain, which dropped 15, and St. Lucia, which dropped 16.
Incorporating data from the Committee to Protect Journalists, Transparency said it found that journalists were in particular danger in corrupt nations.
Over the last six years, more than nine of 10 journalists were killed in countries that scored lower than 45 on the index, and one in five journalists who died was covering a story about corruption.
Looking at data from the World Justice Project, Transparency said it found that most countries that score low for civil liberties also tend to score high for corruption.
"Smear campaigns, harassment, lawsuits and bureaucratic red tape are all tools used by certain governments in an effort to quiet those who drive anti-corruption efforts," said Patricia Moreira, Transparency's managing director.