A British-based charity, the World Society for the Protection of Animals, has amassed evidence that thousands of endangered apes are being slaughtered for their meat and other body parts.
Although all species of great ape, from the common chimpanzee to the rare mountain gorilla, are protected under international conventions and national laws, this has not prevented a flourishing trade in 'bush meat', the name given to the slaughtered game.
Body parts of the apes are also being used in witchdoctor potions. The investigation found, for instance, that the dried hands of gorillas were often ground into powder and sprinkled into babies' baths 'to make them grow strong'.
The society claims that in the Congo Republic alone, up to 600 lowland gorillas and 3,000 chimps are being killed each year. Garry Richardson, the society's director for Africa, warned: 'If these levels of hunting are allowed to continue, man will literally eat the great apes of Africa to extinction.'
It is estimated that the total common chimp population in Africa is between 100,000 and 200,000 spread over 20 countries. The population of the Bonobo pygmy chimp, which lives exclusively in Zaire, is about 20,000. There are fewer than 50,000 lowland gorillas in the Gabon, Congo and Zaire, and just 650 mountain gorillas, which live on the hills of Rwanda, Zaire and Uganda.
The society's year-long investigation found 'vast quantities' of ape meat on open sale in many food markets throughout central and western Africa.
Increased logging of forests in the region had fuelled demand for bush meat by a growing population of migrant workers, the society said. 'Hunters are exploiting the new logging routes and using the timber trucks to transport bush meat to logging townships and to outlying cities.'
Mr Richardson called for the banning of a type of shotgun cartridge, the Chevratine, made by a French munitions company, MACC, based in the Congo.
The Chevratine contains nine lead balls which spread out into a two-foot- wide pattern. 'It is a very efficient killer of apes,' he said.
Measures to protect apes are failing because of the profit from the trade. A gorilla carcass can be sold for pounds 20 and a gorilla hand can fetch pounds 1 - representing small fortunes for poachers.
'A tragic by-product of the bush meat trade is the sale of orphaned apes, often taken whilst still clinging to their mothers, which are sold as household pets,' the society said.
Mr Richardson said orphaned apes were being sold for about pounds 40, mainly to the wealthy expatriate community. For every young animal that survived as an orphan, more than 50 were killed, Mr Richardson said.
Young orphaned animals taken as pets soon became too big and powerful and had to be chained or killed - one such animal had been chained by the neck to a tree for 13 years, he said.
'Chimpanzees are 98.6 per cent genetically identical to humans. They're highly sociable animals, always craving attention. The agony they endure in these conditions is virtually no different to that which a human would suffer.'