By Mark Doyle BBC world affairs correspondent

Chad's new pipeline is more than 1,000km long

The central African state became an oil producer last year.

The committee was set up under a World Bank plan to try to bring transparency to Chad's oil bonanza.

But a senior member said neither Exxon Mobil - which has built a pipeline to export the crude - nor the government were providing sufficient information.

A rather staid anti-corruption conference in London came alive when Therese Mekombe, vice-president of the Chadian oversight committee, got up to speak.

It soon became clear that a whistle-blower had taken the stage.

The committee, she said, was underfunded, understaffed and deprived of information by both Exxon and the Chadian government.

In these circumstances, it could not do the job it was set up to do - which is basically to try to make sure that Chad's opportunity to lift itself out of poverty is not wasted.

Bright side

An Exxon executive - who had earlier presented an optimistic picture of Chad's economy growing strongly as a result of oil revenues - replied that he would be happy to provide any information the committee required.

He said the Chadian economy was set to grow by more than 20% a year as a result of oil revenues.

But Mrs Mekombe continued to paint a negative picture of both the oil company and the Chadian government.

She said her country's natural resources were being exploited in an atmosphere of suspicion and lack of confidence.

Most of the Chadian population, she said, were disillusioned.

The oversight committee is an unusual experiment in public participation.

It was set up with World Bank help to prevent the corruption and environmental degradation that has surrounded oil production in other countries.