US tariffs on imports from developing countries are as much as 20 times higher than those charged on imports from rich nations, according to Oxfam, the development group.

It said an analysis of US customs data showed that the average rate of tariffs on imports from Bangladesh last year was 14 per cent, and duties paid amounted to $301 million (€274 million), although the country supplied only 0.1 per cent of total US imports.

That value was only slightly smaller than the duties paid on imports from France, which bore an average tariff of 1 per cent and accounted for 2.4 per cent of US imports.

US tariffs on imports from India were four to five times higher than on those from Britain. Tariffs on garments, India's second biggest export, averaged 19 per cent.

Oxfam said European Union tariffs also discriminated heavily against developing countries. Its duties on imports from India were about four times higher than on those from the US, and more than eight times higher in the case of Sri Lanka and Uruguay.

"The overall effect of discriminatory tariff systems is to lower demand for goods produced by the poor, and to exclude them from a stake in global prosperity ... northern tariff structures are designed to undermine developing country exports in precisely those areas where they have a comparative advantage," Oxfam said.

The discrepancies arose because wealthy countries imposed high tariffs on many products, such as textiles and clothing, that were a mainstay of developing countries' exports.

They also charged escalating tariffs on products at each stage of processing.

Canada's tariff on fully processed foodstuffs was 12 times that on products in the first stage of processing. The EU tariff on yarn imports was less than 4 per cent, but 14 per cent on garments.

The US and EU charged zero per cent tariffs on imports of raw cocoa beans, but as much as 14 per cent on processed items such as paste and chocolate.

As a result, developing countries produced more than 90 per cent of all cocoa beans, but less than 5 per cent of world chocolate output.

Meanwhile, Oxfam campaigners in Britain yesterday dumped thousands of oranges on the doorstep of the European Commission's London office to highlight demands for an end to the huge subsidies enjoyed by EU farmers.