This link is a little old now, but may help you:
Changes afoot in EU pension regulations QUOTE (Robert O'Connor @ HR Magazine)
In October 2002, the European Court of Justice (ECJ) declared that tax benefits for pension contributions should apply regardless of national borders. The court ruled in the case of Rolf Danner, a dual German-Finnish national, who moved from Germany to Finland and wanted to continue to pay into two German-based pension funds. Finnish authorities claimed he should be subject to taxes on these contributions. Danner argued that the contributions should be regarded, for tax purposes, in the same way as payments made to a Finnish pension.
The court ruled in favor of Danner, saying that EU member states would be wrong either to limit or disallow tax benefits on "contributions to voluntary pension schemes paid to pension providers in other member states."