Reports in Italy this week suggested that Napoli coach Rafael Benitez was preparing to make an offer after being impressed by the defender during the Italian club's Europa League meetings with Swansea.
Williams' agent, Peter Smith, however, insists that talk of a move to Italy is just speculation at present.
"There has been talk of meetings with the club or with Rafa Benitez, but there's no truth in that at the moment," Smith told Napoli Calcio Live.
"Clearly we are talking about a great club with an international level manager, so we are ready to talk to Napoli if a call were to come.
"However, until the possibility becomes concrete, there's no point talking about it."
The 29-year-old's current deal is set to expire at the end of next season.