Australia has been ranked the eighth least corrupt nation in an international ranking of 180 countries.

It has gained one place since last year, in figures released by Transparency International (TI).

New Zealand and Denmark were deemed to have the lowest levels of perceived corruption, while Somalia and Afghanistan had the highest levels.

The Corruption Perceptions Index is based on expert and business surveys to measure the perceived levels of corruption in the public sectors of various countries.

The Berlin-based organisation said countries whose infrastructure had been "torn apart" by conflict needed help from outside to prevent a culture of corruption taking root.

"The international community must find efficient ways to help war-torn countries to develop and sustain their own institutions," TI head Huguette Labelle said.

Overall, the 2009 corruption list is "of great concern," the organisation said, with the majority of countries scoring under five in the ranking, which ranges from zero (highly corrupt) and 10 (very clean).

The most corrupt nation on Earth remained Somalia, the impoverished and war-torn Horn of Africa state that has been without a functioning government for two decades, notching up a score of 1.1.

Full story at http://www.abc.net.au/news/stories/2009/11/18/2745801.htm

Transparency International full list of country ratings at http://www.transparency.org/policy_research/surveys_indices/cpi/2009/cpi_2009_table