Every single company on the London Stock Exchange, bar two, uses round-the-world tax havens, often costing developing countries far more than they receive annually in aid, a report by ActionAid has revealed.

Ninety-eight per cent of the country's biggest businesses are afforded widespread financial secrecy and tax levies by holding jurisdictions in 8,492 companies outside of the UK. This makes up a quarter of the FTSE 100's total 34,000 subsidiaries.

The four big banks (Barclays, HSBC, Lloyds and RBS) alone have 1,649 firms located in tax havens.

ActionAid's research is based on previously undisclosed data. FTSE companies are required by law to disclosed information on their subsidiary businesses, however, ActionAid's analysis found that over half "were not complying with this legal obligation". The child sponsorship chairty submitted complaints to Companies House, thereby forcing Stock Exchange businesses to re-file their annual returns.

A graphic map of the FTSE 100 tax havens can be found on the ActionAid website, here.