Qatar is perceived to be one of the least corrupt countries in the world, according to the latest ranking issued by Transparancy International (TI).

In the TI's latest Corruption Perceptions Index (CPI), Denmark, New Zealand and Sweden topped the list (least corrupt). Qatar, which is ranked 28th on the list, is the least corrupt nation in the Middle East. The UAE is ranked 35, Oman 41 and Bahrain 43.

The index ranks 180 countries according to perceived levels of public sector corruption. The CPI scores countries on a zero to 10 scale, with zero indicating high levels of corruption and 10, low levels.

Corruption in poor countries has created a humanitarian disaster which threatens to derail the global fight against poverty, Transparency International said.

Releasing its annual CPI, the anti-corruption watchdog said donor countries should address the problem by carefully targeting aid.

For the second year running, Somalia and Myanmar received the poorest marks, each scoring 1.4, just below Iraq on 1.5.

Denmark defended its ranking as the world's least corrupt nation, alongside Sweden and New Zealand. All scored 9.3.

TI chair Huguette Labelle called the high levels of corruption in low-income countries a 'humanitarian disaster'.

'Stemming corruption requires strong oversight through parliaments, law enforcement, independent media and a vibrant civil society,' Labelle said in a statement.

 'When these institutions are weak, corruption spirals out of control with horrendous consequences for ordinary people, and for justice and equality in societies more broadly.'    

The Berlin-based watchdog estimated that unchecked levels of corruption would add $50 billion -- or nearly half of annual global aid outlays -- to the cost of achieving the United Nations' Millennium Development Goals on combating poverty.

It urged a more focused and coordinated approach by the global donor community to ensure assistance strengthens institutions of governance and oversight in recipient countries.

TI also singled out the performance of some wealthy exporting countries which saw their scores decline from 2007, saying continued evidence of foreign bribery scandals suggested a broader failure by developed nations.

It said statistically significant declines were seen in 2008 in Bulgaria, Burundi, Maldives, Norway and the United Kingdom, which saw its score dip to 7.7 from 8.4. The UK stood 16th on the list and the US with a score of 7.3 stood 18th.

India with a score of 3.4 ranked 85th; Sri Lanka scored 3.2 and ranked 92nd; Pakistan scored 2.5 (134th rank); Philippines 2.3 (141 rank); Bangaldesh 2.1 (147 rank); and Russia 2.1 (147 rank).

TI said the UK's anti-corruption credentials had suffered a setback following the December 2006 decision to discontinue a criminal investigation of British defence firm BAE Systems in relation to a contract in Saudi Arabia.

Significant improvements were seen in Albania, Cyprus, Georgia, Mauritius, Nigeria, Oman, Qatar, South Korea, Tonga and Turkey.

The following are the scores and ranking of some Middle East states: Qatar 6.5 (28th); UAE 5.9 (35th); Oman 5.5 (41st); Bahrain 5.4 (43rd); Jordan 5.1 (47th); Tunisia 4.4 (62nd); Kuwait 4.3 (65th); Morocco 3.5 (80th); Saudi Arabia - 3.5 (80th); Algeria 3.2 (92nd); Egypt 2.8 (115th); Libya 2.6 (126th); Iran -2.3 (141st); Yemen 2.3 (141st); Syria 2.1 (147th); Iraq 1.3 (178th).