Forestry officers say the reserve is under attack from unscrupulous commercial loggers who work outside authorised zones and do not respect size limits in their quest for maximum financial returns.

"I lack words to describe what is going on here," says Richard Greine, head of the local forestry post, 350 km (220 miles) north of Cameroon's capital Yaounde.

"Both illegal and authorised exploiters have staged a hold-up on the forest."

From central Africa to the Amazon basin and Indonesia's islands, the world's great forests are being lost at an annual rate of at least 13 million hectares (32 million acres) -- an area the size of Greece or Nicaragua.