Greece’s agency for information security on Thursday imposed a €76m (£51.2m, $100.5m) fine on Vodafone’s Greek operation for failing to prevent the illegal tapping of more than 100 mobile phones, including one used by Costas Karamanlis, prime minister.

Vodafone called the decision “unjustified” and said it would appeal. It said the investigation was incomplete because it had not included Ericsson, the Swedish company that supplied the wire-tapping software.