Activists accused the World Bank of failing to ensure that Chad invests new-found oil wealth in development, saying the money had only enriched foreign firms and political elites in one of the world's poorest countries.
The World Bank helped set up what it calls unprecedented safeguards to manage the earnings in Africa's newest oil producer, a test case of whether petrodollars can fight poverty on the continent instead of fuelling conflict and corruption.
But campaigners say they have seen no sign of promised schools and roads since oil began flowing in 2003 via a pipeline through Cameroon built by a consortium led by US-based Exxon Mobil and partly funded by the World Bank.
The $4 billion Doba oil project, with its 1000-km (620-mile) pipeline to the Gulf of Guinea, is one of the biggest foreign investments in Africa.
"I want to tell the World Bank that all the publicity they made around this project has amounted to nothing," said Urbain Moyombaye, head of a group representing the Miandoum area in the southern oil exploiting region of Doba.
"The project is a complete failure. People continue to live in total poverty," he told Reuters, speaking after meeting Cameroonian activists in the Cameroon capital Yaounde last week.
The World Bank issued a statement in July saying it was "very concerned" by findings in a report by Chad's oil revenue oversight committee that cited irregularities in funds transfers, poor service delivery and opaque tender processes.
Chadian activists want the World Bank to take action to improve the monitoring of the oil revenues, which are expected to earn the government $2 billion over 25 years.
"After three years we are not seeing the promised fall-out of the project," said Lydie Beassemda, of Chad's Alternative Research and Monitoring Group, a watchdog run by activists.
"What we expect from the World Bank today is to put pressure on the Chadian government to respect its written undertaking to direct oil revenues to benefit the poor masses," Beassemda said.
Chad's government has accused the consortium of oil firms of selling its crude too cheaply and not respecting a revenue-sharing contract, depriving it of funds.