The United Nations has added its voice to the barrage of criticism on Ethiopia's massive Gibe III hydropower project, calling for work to be suspended until the negative impacts of the dam have been determined.
The World Heritage Committee, which establishes sites to be listed as being of special cultural or physical significance, said the dam's construction endangered the existence of Lake Turkana.
The lake, the largest desert lake in the world and listed as a UNESCO World Heritage Site in 1997, sits astride the Kenya-Ethiopian border.
In a letter to the Ethiopian and Chinese governments after its annual meeting, the committee underlined the importance of Lake Turkana as an outstanding research area for animal and plant communities.
"The area's rich fossil finds have allowed reconstructing the history of animal species and mankind over the past 2 million years," the committee report copied to the Ethiopian government read in part.
Both Ethiopia and China as members of the World Heritage Committee were asked to fulfill their obligations for the protection of such a site.
China is helping fund the building of the dam.
The UN body also asked the governments of Kenya and Ethiopia to invite a monitoring mission to review the dam's impact on Lake Turkana, while encouraging the project's lenders "to put on hold their financial support" until the committee's next annual meeting in June 2012.
The Gibe III dam is being built by an Italian company, Salini Construction, and a Chinese state-owned bank has approved funding for the project, while its export credit agency is financing the erection of transmission lines.
The dam has been the subject of a massive campaign by mainly western rights groups over what they say are negative environmental and social impacts against an estimated 500,000 people in Kenya.
International Rivers, a US-based campaign group, said the project may be one of Africa's worst development disasters" because of the harm it may cause people in the south of the Horn of Africa country.
But Ethiopia has categorically denied the accusation and further signed an agreement with Kenya to export electric power. The transmission line connecting the two countries is nearing completion.
During an international hydropower summit in Addis Ababa recently, Ethiopian Prime Minister Meles Zenawi defended the decision to expand dam projects.
The views of western critics are "ironic" as Ethiopian facilities are "infinitely more environmentally and socially responsible than the projects in their countries, past and present," he said.
Mr Meles articulated his suspicion that there is a conspiracy against hydropower projects in Africa and that those who were advocating against hydropower electricity generation were condemning African and its people to remain in extreme poverty.
"They are concerned about butterflies' lives but not human diseases," he said.
The Ethiopian premier said that most of the activists residing in Europe and North America were not condemning their countries for causing global warming by producing carbon emission gases.
Mr Meles is the current African Union spokesperson on climate change.
Ethiopia has a hydropower potential of 45,000 Megawatts (MW), the second-largest capacity in Africa after the Democratic Republic of Congo, according to the World Bank.
Under a five-year plan, the country plans to raise its power generation to as much as 10,000 MW and expand electricity coverage to 75 per cent of the population, from the current 41 per cent.