The garden furniture is well-made, reasonably priced and marketed as ethically acceptable, but the profits in Wyevale Garden Centres are helping to prop up one of the most ruthless regimes in the world and destroy some of the planet's most precious environments.

The route from the devastated forests of Burma to Wyevale's retail outlets is hidden from customers, but has been traced by Greenpeace. One of the most heavily forested nations in south-east Asia, Burma accounts for 75 per cent of internationally traded teak. Timber is among the biggest sources of income for Burma's military junta, the State Peace and Redevelopment Council (SPDC). Exporting hardwoods accounts for up to 11 per cent of foreign exchange earnings and raises $377m (£200m) a year for firms in the country.

The SPDC retains tight control over logging, awarding businessmen contracts in exchange for their support and extracting "tithes" of up to 25 per cent of export sales. Teak plantations add to the coffers of the military leaders and vast chunks of forest are cut down in an unsustainable way to fund the SPDC's iron grip on Burma's 47 million people.

Human rights organisations say thousands of villagers have been driven from their homes to make way for logging operations, or terrorised into forced labour under military control, often at risk to their lives. Crops have been destroyed to make way for logging camps, adding to the plight of the impoverished Burmese people.

Forestry has also been at the centre of the conflict between the regime and rebel groups on the borders. The SPDC has offered insurgents control over logging in some areas in exchange for ceasefires. The rebels, also hungry for cash, also destroy thousands of acres for profit.

The amount of timber countries say they have imported from Burma is more than double the amount the regime says it has exported, so thousands of tons are being logged illegally. Campaigners say the way in which forests are felled, along with illegal operations and the brutality of the regime, mean that international companies should not be buying timber from Burma.

A spokesman for the lobby group Global Witness said: "There is no independent verification that timber from Burma has been sustainably harvested. Logging in Burma's forests has as much to do with the Burmese government's need to raise foreign revenue as it has to do with sustainability."