Telecoms companies do not have to hand over the names and addresses of users suspected of illegally sharing music online in civil cases, according to a senior legal adviser to the European Court of Justice. 

Advocate General Juliane Kokott said that European law meant that governments should resist handing over personal information unless a criminal case is being pursued.

The advice was given after a court in Spain asked for guidance before ruling on a case between Spanish music publishers' group Promusicae and internet service provider Telefónica. 

The legal opinion could now be quoted by other courts throughout the 27 European nations to rule on similar cases.

Promusicae had asked Telefónica to provide the names and addresses of computer users on the Kazaa peer-to-peer file-sharing service.

Telefónica had argued that personal data could only be shared in criminal prosecutions or in matters of national defence and public security.