Cameroon and Malaysia have failed to make progress in tackling illegal logging since 2010, due to corruption and a lack of transparency and political will, a report by a British thinktank said on Wednesday.
Chatham House has looked into illegal logging and the response of governments and the private sector since 2006.
Cameroon and Malaysia are two of a handful of timber-producing countries - chosen for the importance of the forest sector to their economies and the volume of timber they export - assessed in 2008-09 and again in 2013-14.
"Illegal logging has a devastating impact on some of the world's most valuable remaining forests and on the people who live in them and rely on the resources they provide," Chatham House Senior Research Fellow Alison Hoare said in a statement.
"It is disappointing how little progress Cameroon and Malaysia have made in tackling illegal logging, which exacerbates deforestation, climate change and poverty. In both countries corruption is a major issue, and the governments need to do much more to address the problem."
Illegal logging, one of the main factors driving forest degradation in Cameroon, was much more widespread in the West African nation where entrenched corruption, weak institutions and unclear laws were impeding reform, Chatham House said.
"The big issue is the lack of clarity between the legal framework for forestry, agriculture and mining and lack of coordination between those sectors, which means that you end up with rights being allocated to the same area of land for different uses, so then there's a dispute as to who has the rights to it," Hoare told the Thomson Reuters Foundation.
Forty percent of Cameroon's land is forested. Half of the timber produced in the country comes from the informal sector, and nearly all of that is illegal, resulting in forest degradation, Hoare said.
Another problem is the misuse of "small permits", which are often granted to allow the clearance of forests for infrastructure or farming projects, by businesses that see it as an easier way to get timber, Hoare added.
Chatham House said illegal logging in Malaysia, where 60 percent of the land is forested, was not as bad as in Cameroon. But problems persisted in the largest state of Sarawak, which is rich in resources.
The growth of timber, pulp and agricultural plantations is driving forest loss in the Southeast Asian nation, where the area given over to plantations is expected to double by 2020, the report said.
By contrast, Ghana and Indonesia had made much more progress in tackling illegal logging, Hoare said.
"In Indonesia this agenda has become closely linked with the government trying to reduce its carbon emissions and its deforestation (as part of the) whole climate change issue which it has been giving a lot of priority to," she added.
A study last week showed that Indonesia's moratorium prohibiting district governments from granting new palm oil, timber and logging concessions had lowered greenhouse gas emissions from deforestation by 1 to 2.5 percent between 2011 and 2015.
However, Indonesia will not meet its emissions reduction target of 26 to 41 percent by 2020 unless the current policy is extended and strengthened, according to researchers from the Center for Global Development and others.