Silvio Berlusconi was accused of deliberately impeding the trial in which he is charged with buying sex from a minor and abuse of power, after the key witness failed to turn up yesterday.
Karima "Ruby" El Mahroug, the young bellydancer at the centre of the allegations, did not appear at the court in Milan.
Her lawyer, Paola Boccardi, said: "I tried to get in touch with the girl, but her cell phone is off, as is her boyfriend's. She sent me an SMS saying she is abroad, but I do not have documentation of this trip and I don't know when she will return."
Ilda Boccassini, for the prosecution, accused the defence of using delaying tactics for political reasons. "This is a strategy to delay the proceedings while the election campaign gets under way," the lawyer said.
Niccolo Ghedini, for Mr Berlusconi, said Ms Boccassini's comments were an "intolerable attack on the defence".
In April records of bank transactions revealed that the billionaire media mogul had paid a total of €127,000 to three key witnesses shortly after the Rubygate trial had begun. He denies the sex and corruption charges.