Barcelona have been linked with a move for the Belgium international as they look to bring in a replacement for Carles Puyol.
Vertonghen's future at White Hart Lane has been the subject of speculation for some time after Tottenham missed out on the Champions League for next season.
Vertonghen has four years left on his contract and Sky sources understand Spurs have no intention of selling him.
Vertonghen's representative, Mustapha Nakhli, refused to confirm if Barcelona were one of the clubs interested in the defender and he does not rule out a move for the former Ajax defender.
"Several teams are interested in Jan," Nakhli told Het Nieuwsblad. "I cannot confirm or deny whether Barcelona are one of them.
"Tottenham is not a small club. It's too soon to give them an answer. Several clubs have registered their interest in Jan. We'll see."