The conversation took place between the head of insurer Unipol and Piero Fassino, who was the leader of the biggest centre-left party and Mr Berlusconi's biggest political rival at the time.
Quite apart from the potential damage it may do to the centre-left's election hopes, Mr Fassino's involvement with Unipol threatens further to dent Italy's reputation in the international business world, already battered by the Parmalat and Fazio affairs.