Transparency International
The Corruptions Perception Index ranks each country based on their transparency.Transparency International

Despite a concerted and official effort to clamp down on graft, China has fallen behind Zambia, Armenia and Liberia in the ranks of the world's most corrupt countries.

Transparency International's latest Corruptions Perception Index – a respected ranking of 176 of the world's countries – shows that public sector corruption is systemic in China. Central to exposing the country's graft was a cache of documents leaked to the International Consortium of Investigative Journalists, which showed 22,000 instances of high-profile Chinese siphoning public money to offshore tax havens.

The files included details on a real estate company owned by President Xi Jinping's brother-in-law and companies setup in the British Virgin Islands by the son of former Premier Wen Jiabao.

"Grand corruption in big economies not only blocks basic human rights for the poorest but also creates governance problems and instability. Fast-growing economies whose governments refuse to be transparent and tolerate corruption, create a culture of impunity in which corruption thrives," said Transparency International chair José Ugaz.

Other countries to have slid down the ranks of transparency include Turkey and Angola. In 2013, a criminal investigation was launched involving several key figures in the Turkish government. Among the transgressions being investigated are bribery, corruption, fraud, money laundering and smuggling. Turkey is now below Saudi Arabia, Rwanda and Cuba in the ranking.

The most corrupt state in the world is Somalia, followed by North Korea, Sudan, Afghanistan and South Sudan. The most transparent is Denmark, just ahead of New Zealand, Finland, Sweden and Norway.

The UK is 14th, sandwiched between Iceland and Belgium, while the US ties with Barbados, Hong Kong and Ireland for 17th position in the rankings.

At a time in which few major countries are performing well, economically, Ugaz warned that economic growth is being undermined by corruption.

"The 2014 Corruption Perceptions Index shows that economic growth is undermined and efforts to stop corruption fade when leaders and high level officials abuse power to appropriate public funds for personal gain," he said.

"Corrupt officials smuggle ill-gotten assets into safe havens through offshore companies with absolute impunity," Ugaz added.

The Corruption Perceptions Index is based on expert opinions of public sector corruption. Countries' scores can be helped by open government where the public can hold leaders to account, while a poor score is a sign of prevalent bribery, lack of punishment for corruption.