Lazio director Igli Tare said fans have leaked his phone number, sent harassing messages and booked fake plane tickets.
The director of sport spoke to Il Tempo newspaper after he personally tried to calm a crowd of furious fans when the club lost transfer target Davide Astori to rivals Roma this week.
“After that night at the Auronzo di Cadore camp and the confrontation with the fans over Astori, the trouble really started,” explained Albanian former striker Tare.
“Someone must’ve got hold of my phone number, as I found it on the internet. The usual threatening messages started arriving, but not just those.
“There were strange calls, like one from Alitalia because somebody had booked a flight to Rotterdam in my name. I spent two hours trying to undo it and figure out who had done this.
“Over the next few days I’ll be forced to change my phone number again, which won’t be an easy task as that is a fundamental instrument in my work.
“Many problems are emerging, but what upsets me the most are the things said to my family.”
It is likely the flight to Rotterdam was a hint from ultras, as Tare is meant to be in negotiations with Feyenoord for defender Stefan De Vrij.
Nonetheless, Lazio are expected to lose out again, this time to Manchester United.