New Zealand ranked least-corrupt country in the world, again

New Zealand has been named the least-corrupt country in the world.

Transparency International on Thursday released its latest Corruptions Perception Index, which rates countries on their "perceived levels of public sector corruption according to experts and businesspeople".

New Zealand's score slipped from 90 to 89 (out of 100), but remains marginally ahead of Denmark, which scored 88. New Zealand was ranked first-equal with Denmark last year on 90.

Somalia once again came last, its score dropping from 10 to nine. Syria and South Sudan were barely better, scoring 14 and 12 respectively.

Transparency International NZ's David McNeill said Kiwis should be proud of their ranking.

"They understand what a fair go is, and nobody likes to see corruption where resources are transferred from the many to the few."

But more work would be needed in order to stay on top. 

"We can only maintain that position from ongoing improvement."

Other countries ranked highly were Finland, Norway, Switzerland, Singapore, Sweden, Canada, Luxembourg, the Netherlands and the UK. Not surprisingly, Western Europe was the least corrupt region of the world.

But more than two-thirds of the 180 countries in the list scored below 50, with the average score a lowly 43. South Africa scored 43, so if you think South Africa is corrupt, it's not an exception - it's the norm.

Sub-Saharan Africa, the Middle East and central Asia ranked the worst however, with Somalia, South Sudan, Syria, Afghanistan, Yemen, Sudan, Lybia, Guinea Bissau, Equatorial Guinea, North Korea, Iraq, Turkmenistan and Venezuela bringing up the rear.

Countries that have improved since last year include the Ivory Coast, Senegal and the UK. Syria, Yemen and Australia all slipped.

US President Donald Trump has been accused of various forms of corruption. Photo credit: Getty

The US ranked 21st, with a score of 75 - up one point and one place in the rankings, perhaps surprising critics of US President Donald Trump and his administration. Australia ranked 16th, Israel 36th and Cuba 65th.

Why New Zealand is the least-corrupt country in the world

Transparency International NZ chair Suzanne Snively said New Zealand's performance reflects the "integrity of our public servants".

"Complacency however remains our biggest challenge. The prevention of corruption is too often a low priority.

"Work to enhance transparency must continue for New Zealand to maintain leadership in the fight against corruption. This includes more open public involvement in Government decision-making and a publically accessible registry of the beneficial owners of companies and trusts."

Transparency International patron and former Commonwealth Secretary-General Don McKinnon said New Zealand has "strong integrity systems in place".

"A perceived lack of corruption and active examples of good business practices make it easier for Kiwi organisations to gain market access offshore, all of which ultimately benefits all New Zealanders."

The world's least-corrupt countries

1. New Zealand
2. Denmark
3. Finland, Norway, Switzerland
6. Singapore, Sweden
8. Canada, Luxembourg, The Netherlands, The UK

The world's most-corrupt countries

1. Somalia
2. South Sudan
3. Syria
4. Afghanistan
5. Yemen, Sudan
7. Libya, Guinea Bissau, Equatorial Guinea, North Korea