Berlusconi's lawyer Niccolo Ghedini said the news that the prime minister had been invited this month to answer prosecutors' questions -- published on the front page of leading daily Corriere della Sera -- was leaked as a political tactic against him as Italy moves towards elections next spring.
Under Italian law, prosecutors can either invite or summon a person to answer questions. A person who is invited has the right not to appear.
Magistrates have been investigating since March whether Berlusconi offered money to David Mills, husband of British Culture Secretary Tessa Jowell, to prevent him from revealing details of his dealings with the prime minister's media empire.
Mills has denied wrongdoing. His lawyer was not available for comment on Thursday.
An invitation to appear for questioning usually comes at the end of a judicial investigation. Corriere della Sera said magistrates could close the investigation next month and ask a judge to send suspects to trial.
Berlusconi, Mills and 12 others are already under investigation in a related fraud case involving Berlusconi family's broadcaster Mediaset. Preliminary hearings to decide whether to indict them began in October.
Under Italian law, public prosecutors investigate suspected crimes but it is up to a judge whether the accused are charged and must stand trial.
Berlusconi, who created Italy's largest media empire, has been tried on at least seven occasions for graft. He has never received a definitive guilty verdict.
Mills has testified as a witness at three of Berlusconi's fraud trials -- a trial into funds transferred to offshore firm All-Iberian, a trial into alleged bribery of tax inspectors by Berlusconi family holding Fininvest, and a trial into the bribing of judges to influence the outcome of the sale of the SME food chain.
Berlusconi accuses prosecutors of leading a politically motivated witchhunt against him and his family.