The Dutch government has failed in its appeal against a recent court decision banning the AIVD secret service from tapping lawyers’ telephones.

Under European law, lawyers’ phones may be tapped directly if they themselves are the target of an investigation, or indirectly if they are phoned by someone who is being watched by the security services.

However, there must be an independent watchdog to assesses if the law is being applied correctly and it requires very special circumstances to approve such a tap, the court said.

The Netherlands, however, has no independent monitoring body, rendering lawyer phone taps illegal. In July, the lower court gave the AIVD six months to officially change its current practices and warned that if the AIVD does not comply, it will be banned from tapping lawyers’ phones altogether.

The case was brought by criminal law firm Prakken d’Oliviera, which discovered last year that the AIVD had been listening in to conversations since 2003. The security service regulator has already said some of the phone taps were illegal.