'A global super-rich elite has exploited gaps in cross-border tax rules to hide an extraordinary £13 trillion ($21tn) of wealth offshore – as much as the American and Japanese GDPs put together – according to research commissioned by the campaign group Tax Justice Network.

James Henry, former chief economist at consultancy McKinsey and an expert on tax havens, has compiled the most detailed estimates yet of the size of the offshore economy in a new report, The Price of Offshore Revisited, released exclusively to the Observer.'

Read more: £13 Trillion: Hoard Hidden From Taxman by Global Elite