Kane has been linked with a move to Real Madrid as the Spanish giants are planning an major overhaul of their squad this summer in order to close the 15-point gap to Barcelona in La Liga.
Real Madrid have also been linked with Bayern Munich striker Robert Lewandowski, but it is believed Kane is their main target.
“The objective for Real Madrid, no doubt, is Kane,” Ramon Calderon told The Sun.
“If they want a player for the next five or six years they are going to go for Kane but [Spurs chairman Daniel] Levy is going to ask a fortune for him.
“As far as I know, Tottenham is not willing to let him go but Bayern also say Lewandowski is not going anywhere.
“[Bayern chief executive Karl-Heinz] Rummenigge has said he can bet that he will be in Bayern next season but we have heard that so many times, and in my experience it is the player who has the final decision of where to go.”
