Forty million fridge freezers were imported from China into the EU at a unit cost of just 18p each between 2005 and 2007. Valuable electronic resistors were exported to the US from Malaysia at less than one cent apiece. These are just two of the examples of how multinationals misprice goods as they trade them around the globe, often between their own subsidiaries, in order to avoid billions of pounds of tax, according to research commissioned by Christian Aid.

In a report, the charity analyses international trade data between 2005 to 2007 to show that £581.4bn has passed to EU and US countries from non-EU and developing countries thanks to the mispricing of imports. If tax had been levied on that capital at current rates, countries outside the EU would have been able to raise £191bn in revenue. The mispricing of fridge freezers from China imported into Spain resulted in China losing £5.53bn of revenue from this trade alone, the authors claim.

About 60% of world trade now takes place within rather than between multinational corporations. When transactions take place within a group of companies with the same parent, the price at which they are concluded is covered by a system called "transfer pricing". As part of the price, subsidiaries may be charged fees for intellectual property rights, management services, use of brands and logistics expertise. These services are meant to be determined "at arm's length" or at the rate that the open market would charge.

Christian Aid's report, False Profits: Robbing the Poor to Keep the Rich Tax-free, has found that abuses of transfer pricing appear frequently in the trade data. Subsidiaries in some countries appear to be charging vastly reduced rates for goods or services to minimise their tax liabilities.

"The way fees are determined has become increasingly opaque as arm's length pricing is forgotten and the figures are manipulated to reduce tax," said David McNair, Christian Aid's senior economic adviser and author of the report. "Paying as little tax as possible has for many become an acceptable way of doing business."

The charity asked Professor Simon Pak, president of the Trade Research Institute in the US, to analyse data on global bilateral trade with the UK, Republic of Ireland, the rest of the EU, and the US, looking at official records for prices of imports from products from nuclear reactors to cornflakes. He calculated the normal price range for products traded between counties and estimated the amount of capital shifted by trades that were well outside that normal price range.

Among the biggest losers of tax revenue from this capital flight between 2005 and 2007 were Nigeria, Pakistan, Vietnam and Bangladesh. Instances of mispricing were found on a huge range of goods, from oil and minerals to parts for electronic goods, agricultural commodities and pharmaceutical products.