Hervé Falciani, the IT specialist who revealed the identity of thousands of Swiss bank account holders, is apparently collaborating with Spanish secret services (Centro Nacional de Inteligencia, CNI).

Spanish prosecutors have refused to act on a Swiss demand to extradite the Franco-Italian, who was conditionally released in December 2012 and told to report to police every three days, arguing that he is "actively collaborating" with secret services in Spain and other European countries.

El Mundo believes that the Spanish government could exercise a veto on any decision to extradite the former HSBC employee.