Milan, Italy  - Italian authorities on Tuesday began interrogating suspects linked to a private Milan clinic where unnecessary surgery, allegedly performed to obtain state money, is believed to have led to the deaths of five patients.

Investigators uncovered the alleged plot, involving 14 doctors at the Santa Rita clinic and its owner, after intercepting telephone conversations.

Medical records seized at the clinic were also found to have been falsified to motivate operations, with some 88 patients subjected to unnecessary surgery over the past two years, prosecutors say.

Police on Monday took into custody two senior doctors while other suspects were served with house arrest orders.

Charges include manslaughter, causing bodily harm and fraud committed against Italy's national health system.

Prosecutors estimate illicit profits at the San Rita clinic amounted to some 2.5 million euros (3.9 million dollars).

Riziero Scocchetti, 72, told the La Repubblica newspaper, he became suspicious when his 65-year-old sister, who had been diagnosed with incurable breast cancer, had a lung removed at the Santa Rita clinic just eight days before she died in December 2006.

"I begged the doctors to let her die in peace, instead they went ahead with the operation ... even if everyone knew she wasn't going to make it," Scocchetti told the Rome-based daily.

One 21-year-old woman, identified only by the name Domenica, had a breast removed three years ago in a mastectomy which prosecutors believe was performed for the sole purpose to claim state funds.

"If all this is true, then we would be facing something which is horribly criminal," Lombardy Region President, Roberto Formigoni, said.

Investigators say the use of phone taps was crucial in uncovering the alleged scam, adding fuel to a controversy in Italy around plans by the government to limit such forms of surveillance.

Prime Minister Silvio Berlusconi has repeatedly criticized magistrates for what he calls the "excessive use" of telephone interceptions, specifying they should should be restricted to investigations involving the Mafia and terrorism. (dpa)