Mr Berlusconi stands accused of bribing judges in the 1985 takeover of the state-owned SME food company.
Long-time rivals, Commission President and former Italian Prime Minister, Romano Prodi and current incumbent Silvio Berlusconi will face a tense working relationship in July, when Italy takes over the Presidency of the European Union, after Mr Berlusconi made accusatory statements against Mr Prodi in his fraud trial on 5 May.
Mr Prodi reacted to the accusations, stating that "the matter has no bearing on the case". "I believe those in public office have a duty to give a full and open account of their actions. I have never shirked my responsibility in this respect, either when I was in office in Italy or now that I hold office in the European institutions," said President Prodi.
The SME food company had been put on the market by state holding company IRI, which at the time was run by Mr Prodi. Mr Berlusconi is accusing Mr Prodi of side-stepping IRI's board in the deal and negotiating a much lower closing sum with left-wing industrialist Carlo de Benedetti. According to Mr Berlusconi's statement, then-Italian Prime Minister, Bettino Craxi, was concerned about the low sales price, and personally requested Mr Berlusconi step in and make a higher offer "because the operation damaged the state." De Benedetti's attempts at foiling the deal through legal action was blocked, which prompted the accusations of bribery against Mr Berlusconi in 1995.
Mr Berlusconi's hearing comes only six days after his personal lawyer and previous justice minister, Cesare Perviti was sentenced to 11 years' imprisonment on bribing judges in two takeover bids.