Corruption is on the rise in some rich countries as well as poorer ones, research by anti-corruption watchdog Transparency International suggests.
Corruption leads to much-needed resources leaking overseas
The group's Corruption Perceptions Index labels Bangladesh and Chad as the most corrupt places on the planet.
The situation worsened in countries such as Costa Rica, Russia and Sri Lanka - as well as Canada and Ireland.
But nations and areas where perceptions of corruption are declining include Hong Kong, Turkey and even Nigeria.
TI's survey asks businesspeople, academics and public officials about how countries they live in or do business with are perceived.
The results are used to gauge how corrupt public officials are. The CPI does not deal directly with private-sector corruption.
At both the top of the list and the bottom, the index shows little change from 2004.
Topping the list, the cleanest countries are Iceland, Finland and New Zealand, with Switzerland not far behind.
The UK is equal 11th with the Netherlands, with the US back at 17.
Bangladesh and Chad - joint 158th - share the bottom end of the table with the likes of Haiti and Turkmenistan.
Several other parts of the former Soviet Union also fare badly. Russia itself is joint 126th, while Georgia, Kyrgyzstan, Azerbaijan, Uzbekistan and Tajikistan rank even lower.
Resource-rich African states are seen as particularly corrupt, the CPI says. Nigeria, Angola, Equatorial Guinea, Sudan and the Democratic Republic of Congo are all in the bottom 20.
But Nigeria has managed to move up the rankings, from being ranked third-bottom last year.
TI said the survey demonstrated that the corruption continued to threaten development by hampering growth and putting off investors.
"Corruption is a major cause of poverty as well as a barrier to overcoming it," said TI chairman Peter Eigen.
THE BEST AND THE WORST
5 least corrupt states:
5 most corrupt states:
Source: Transparency International
"The two scourges feed off each other, locking their populations into a cycle of misery."
But although poor countries stood to gain the most from fighting corruption, TI said richer countries needed to take responsibility too, by investigating and prosecuting companies suspected of corrupt practices abroad and barring them from public contracts.
Corruption has been high on the official development agenda for some years, but campaigners have often argued that governments only pay lip-service to it.
Recently, however, attitudes appear to be changing.
The United Nations Convention against Corruption comes into force in December 2005, enshrining in international law rights to pursue looted resources sent overseas.
In the UK, the government's Commission for Africa has called for a much tougher line on the proceeds of corruption and their repatriation.
Similarly, London's Metropolitan Police is working on an initiative to strengthen economic crime prevention, including anti-corruption activities, across the Commonwealth.