Italy's justice minister has started an investigation into whether government officials were involved in an alleged wire-tapping scandal at Telecom Italia.
Telecom Italia has been in the headlines in recent weeks
The news comes a day after police said they had arrested 20 people as part of an investigation into the case.
Prosecutors say the spy ring taped the phone conversations of politicians, industrialists and even footballers.
The scandal has come to light days after Telecom Italia said it planned to spin off its TIM mobile phone network.
Among those arrested by police include a former chief of security at Telecom Italia, Giuliano Tavaroli, as well as the head of a private investigation agency in Florence.
Prosecutors say that evidence of illegal wiretapping stretches back to 1997, with magistrates, celebrities and football referees also being targeted.
They claim to have discovered "tens of thousands" of names on seized computers and documents, but have released no more details.
Politicians from both sides of Italy's political divide have demanded quick answers.
"What we are in the process of discovering is disturbing, and that is that Telecom Italia sheltered one of the biggest private spying organisations this country has ever known," said Pino Sgobio, parliamentary whip of the Communist Party, part of Romano Prodi's ruling coalition.
The scandal has also fuelled speculation about the full reasons behind the planned sale of TIM, the last remaining Italian-owned mobile phone network.
Former Telecom Italia boss, Marco Tronchetti Provera, resigned over the issue last week, after Mr Prodi came out publicly against the split move.
An advisor of Mr Prodi also subsequently stood down after leaked papers appeared to suggest that the Prime Minister was wrong to say he had received no prior notification of Telecom Italia's plans.
Italy's leading newspaper, the Corriere della Sera, has described the wire tapping scandal as "the most powerful private spy organisation ever discovered in Italy".