Public servants have been told they have a right to celebrate, but can't become complacent after New Zealand was ranked the least corrupt country in the world.
New Zealand jumped three places to share top spot with Denmark in Berlin-based Transparency International's 2016 Corruption Perceptions Index.
Both scored 90 in an index that ranks 176 countries on a scale of zero to 100. Somalia is at the bottom of the list, scoring just 10.
Last year, New Zealand ranked fourth with 88 after previously leading the league table.
TI New Zealand chair Suzanne Snively says the country's public sector agencies have focused successfully on developing processes that prevent corruption.
"New Zealand trades on its low corruption reputation and we are increasingly finding how to transfer these behaviours from our public to our private sector to leverage off this enviable reputation for integrity," she said.
"Our public servants from throughout the country have a right to celebrate this news. The TI CPI proves that they are working to do a good job preventing corrupt behaviour."
But she also said the biggest challenge to maintaining a top ranking had been a tendency to become complacent.
The prevention of corruption could be regarded as a lesser priority, given other pressures, including earthquakes, the global financial crisis and the consequent reductions in baseline funding.
Justice Minister Amy Adams said it was encouraging to see New Zealand reclaim top spot, having held it for eight of the last 10 years.
"The result reflects New Zealand's zero-tolerance of bribery and corruption, and affirms our reputation as world leaders in this area," she said.
Ms Adams said the government had implemented a number of anti-corruption initiatives.
These included new bribery offences and increased penalties, fast-tracking a second phase of anti-money laundering reforms and ratifying the United Nations Convention Against Corruption.
LEAST CORRUPT COUNTRIES
1= New Zealand 90
1= Denmark 90
3 Finland 89
4 Sweden 88
5 Switzerland 86
6 Norway 85
7 Singapore 84
8 Netherlands 83
9 Canada 82
10= Germany 81
10= Luxembourg 81
10= UK 81
MOST CORRUPT COUNTRIES
176 Somalia 10
175 South Sudan 11
174 North Korea 12
173 Syria 13
170= Yemen 14
170= Sudan 14
170= Libya 14
169 Afghanistan 15
168 Guinea-Bissau 16
166= Venezuela 17
166= Iraq 17
Source: Transparency International's 2016 Corruption Perceptions Index 2016.