By Tony Cheng
BBC correspondent in Bangkok
Illegal logging by Chinese timber companies is devastating large stretches of Burma's forests, an environmental watchdog has claimed.
A report by Global Witness said the illegal lumber exports to China were destroying some of the most bio-diverse and temperate forest in the world.
The report alleges that the illicit trade is going on with the knowledge of the Burmese and Chinese authorities.
China's rapid growth is devastating Burma's environment, it said.
Fifteen tonnes of illegally logged timber is passing over the Burmese border into China every seven minutes, 24 hours a day, every day of the year, the report said.
Ninety-five percent of it is illegally exported, Global Witness said.
China signed a commitment to address concerns over illegal logging in 2001, but is has since more than doubled its consumption of illegal Burmese timber, Global Witness said.
Both the Chinese and Burmese governments have declined to comment on the allegations.
Smuggled goods of all sorts pass relatively freely across the Burmese border into China because of widespread corruption amongst the military officials that control the area.
A year ago, Burma's former Prime Minister Khin Nyunt was removed from his post following allegations that he had controlled and profited from many of the smuggling routes.