China has ranked last in a global aid transparency index for the second year running, as most countries were criticised for failing to provide enough information about their activities.

The index, compiled by the international NGO Publish What You Fund, ranked 68 countries in terms of openness over aid funding.

China was joined at the bottom the list by Greece, Cyprus, Lithuania and Malta, all of which were among bottom 10 in 2013's survey.

The index analysed transparency from 68 aid-funding operations across the globe, including countries like the United States and China, as well as non-governmental organisations like The World Bank and the United Nations.

"The ranking shows that no matter how many international promises are made, and no matter how many speeches there are around openness, a startling amount of organisations are still not publishing what they fund," said Rachel Rank, director of Publish What You Fund, said in a statement.

While some organisations had made significant progress, Rank said, more than half had shown little progress since last year's report, while almost a third were classified as 'very poor,' meaning they had not demonstrated a concrete plan to increase transparency.

The worst offenders had failed to approach transparency systematically, with available data being buried in PDF files or being incomplete, the report said.

"This means there is still a long way to go in obtaining a full picture of all development flows, without which development effectiveness and improved donor coordination will be difficult to achieve," the report said.

The United Nations Development Programme ranked first place in the index, followed by the UK Department for International Development.