An international drive against offshore tax havens has reaped nearly 14 billion euros from would-be tax evaders, the Organization for Economic Cooperation and Development (OECD) said on Tuesday.

Some 100,000 taxpayers in 20 major economies surveyed by the OECD have revealed previously undetected offshore assets in the last two years, allowing tax authorities to collect the equivalent of nearly $19 billion.

As cash-strapped governments look to pay down their deficits, this will make a substantial contribution to fiscal consolidation, OECD Secretary General Angel Gurria said at the opening of a two-day meeting on tax transparency.

Just as important -- most of the additional revenues has been secured from citizens trying to evade taxes, he added. At a time when many governments are forced to ask their citizens to accept higher taxes and reduced public services, everyone must pay their fair share.

Italy has so far been the biggest beneficiary of the crackdown. An scheme there to promote voluntary disclosure of offshore assets had helped bring in additional tax revenues of 5.6 billion euros, the OECD said.

A similar scheme in the United States helped recover 2.7 billion dollars from more than 30,000 taxpayers. Germany had raised additional tax revenues of 1.8 billion euros from as many as 30,000 taxpayers.

Berlin is expected to net billions more from a recent deal to formalize the taxation of money stashed by German citizens in secret Swiss accounts.

Switzerland reached a similar agreement with Britain earlier this month is inching toward a settling a dispute with the United States over Swiss banks helping wealthy Americans to dodge taxes.

The Group of 20 countries agreed at a summit in London in 2009 to step up efforts to clamp down on offshore tax havens. The OECD has since led efforts to force such jurisdictions to sign international standards on data disclosure, and publishes lists exposing those countries that refuse to comply.

The OECD said the number of requests for tax information from jurisdictions previously considered to be tax havens had surged from nearly zero into the thousands, with Switzerland alone getting hundreds of requests since 2009.

($1 = 0.720 Euros)

(Reporting by Leigh Thomas; Editing by John Stonestreet)