AUSTRALIA is the least corrupt country in the Group of 20 industrialised nations but New Zealand is top of the global list overall, in a year marked by anti-government protests in Europe and the Middle East.

Transparency International, a global organisation leading the fight against corruption, says its annual league tables show New Zealand in first position as the least corrupt country in the world.

Denmark and Finland tied at second place, coming in before Sweden at number four and Singapore at number five.

Australia remains in joint eighth position with Switzerland.

In 2010, Australia's trans-Tasman neighbour was ranked joint first with Denmark and Singapore, which now stand at second and fifth respectively.

Transparency International's Corruption Perceptions Index scores 183 countries and territories from zero (highly corrupt) to 10 (very clean) based on data from 17 surveys that look at factors such as enforcement of anti-corruption laws, access to information and conflicts of interest.

Two thirds of ranked countries scored less than five.

New Zealand, which is not part of the G20, scored 9.5 compared to 9.3 last year, while Australia achieved 8.8, up from 8.7.

At the other end of the scale, joint last were North Korea and Somalia, both scoring just one point.

Transparency International warned the protests seen around the world in 2011, mainly fuelled by corruption and economic instability, show citizens feel their leaders and public institutions were neither transparent nor accountable enough.

"This year we have seen corruption on protesters' banners, be they rich or poor," the organisation's chair Huguette Labelle said while releasing the report in Berlin today.

"Whether in a Europe hit by debt crisis or an Arab world starting a new political era, leaders must heed the demands for better government."

Australia's number-one trading partner China was ranked 75th in the world with a score of 3.6, while its number-two trading destination Japan was 14th with a score of 8.0.

The largest economy in the world, the United States, was 24th with a score of 7.1.

20 least corrupt countries:

1. New Zealand



2. Denmark

2. Finland



4. Sweden



5. Singapore



6. Norway



7. Netherlands



8. Australia

8. Switzerland



10. Canada



11. Luxembourg



12. Hong Kong



13. Iceland



14. Germany and Japan



16. Austria,

16. Barbados

16. United Kingdom



19. Belgium

19. Ireland

20 most corrupt countries

1. Somalia



1.North Korea



3. Burma



3. Afghanistan



5. Sudan



5. Turkmenistan



5. Uzbekistan



8. Haiti



8. Iraq



10. Burundi



10. Equatorial Guinea



10. Venezuela



13. Chad,



13. Libya



13. Angola



13. Democratic Republic of Congo



17. Cambodia



17. Guinea



17. Kyrgyzstan



17. Yemen