Inter are accused of tailing De Santis -- currently serving a five-year ban for his involvement in the Italian match-fixing scandal -- between the end of 2002 and the beginning of 2003.

The club are said to have been suspicious of De Santis' relationship with former Juventus general manager Luciano Moggi, the central figure in the match-fixing scandal who was banned from sport for five years.

If found guilty of spying on De Santis, Inter could face sanctions from the Italian football federation (FIGC).

"The (spying) activity was commissioned by Inter, by its directors who turned to Tavaroli and (Emanuele) Cipriani of the detective agency Polis d'Instinto," Massimo Dinoia was quoted as saying in Monday's Gazzetta dello Sport.

However, Mario Stagliano, the former deputy of the FIGC's match-fixing investigation, believes Inter will not be punished even if they are found guilty of tailing De Santis.

"Inter will not suffer any kind of consequence, they're not at risk," he said in a radio interview on Monday.

"Even if it emerges Inter acted illegally, it has been four years since the alleged spying and the law only applies to what has happened in the past two years. The maximum punishment would be a fine."

Tavaroli, head of Telecom Italia's security operations until May 2005, was arrested last month in connection with the company's alleged phone-tapping.

Telecom Italia are suspected of tapping the phones of thousands of clients, including celebrities and high-profile footballers.

Also arrested were Cipriani and Pierguido Iezzi, the current head of security for Telecom Italia's major shareholder Pirelli, who have a large stake in Inter Milan.

Francesco Saverio Borrelli, head of the FIGC's match-fixing investigation, will speak to De Santis later on Monday before talking to Inter Milan owner Massimo Moratti on Tuesday.

De Santis has accused Moratti of hiring a private detective to tap his and his wife's phones; claims the Inter owner vehemently denies.

"I can confirm that I never sent anybody to follow anyone," Moratti said last week.

Inter, who finished third in Serie A last season but were awarded the title after Juventus and AC Milan were penalised for rigging matches, were not implicated in the match-fixing scandal.

The scandal involved clubs, referees and high-ranked FIGC officials and resulted in the relegation of Juventus to the second division with a 17-point penalty.

The four other clubs found guilty of sporting fraud -- AC Milan, Lazio, Fiorentina, and Reggina -- kept their status in Italy's top division but were all deducted points.