James Cook University rainforest ecologist Professor William Laurance has warned ''vague labels such as 'Made in China' are not helpful'' to consumers - and are likely to be misleading - given China's dominant role in the global illegal timber trade.

Although manufactured in China, the products could be made from timber harvested illegally in Africa, South America, Asia or Papua New Guinea.

Professor Laurance, a former chief research scientist with the Smithsonian Institution in the United States, is visiting Canberra to brief members of the Senate rural affairs committee today on the economic and environmental impacts of illegal logging of tropical timber in developing countries.

Speaking at the Australian National University yesterday, he said eco-certification programs such as the Forests Stewardship Council did ''not go far enough'' to protect tropical forests from illegal logging, and mostly applied to timber harvesting in temperate regions. Less than 5per cent of tropical timber is currently eco-certified as being obtained from a sustainably harvested source, he said.

''The current eco-labelling accreditation schemes are a long way from perfect, and need to be improved. Then you have countries like Indonesia and Malaysia that have developed their own accreditation schemes, but in several instances, these have been shown to be fairly lax.''

Professor Laurance said China had developed ''an immense export'' market for wood and paper products, driving large-scale clearing of tropical forests in Sumatra and Borneo.

''During a recent visit to Sumatra, I witnessed the felling of large expanses of native rainforests, which are being chopped up and fed into the world's largest wood-pulp plant, located nearby, and replaced by monocultures of exotic acacia trees,'' he said.

China had ''done little to combat the scourge of illegal logging'', and is estimated to have imported between 16 and 24million cubic metres of illegal timber each year over the past decade. ''That is an incredible figure, twice the amount imported annually by leading industrial nations.''

Professor Laurance said that while Chinese government agencies had commissioned an analysis of China's role in the illegal timber trade, there was no national plan or laws to prevent the import of illegal timber.

He warned a Senate inquiry into Australia's proposed new timber import laws to expect ''influential lobbyists'' to oppose efforts to combat illegal timber imports under the banner of free trade.

''On close inspection it quickly became apparent that these lobbyists are usually paid by foreign timber and wood-pulp corporations that benefit directly from illegal logging,'' he said.

According to a report by Interpol and the World Bank, illegal or ''predatory logging'' is estimated to defraud developing nations of about $15 billion each year in tax and timber royalty evasions.