The 22-year-old has become a mainstay in the heart of Marseille's defence since his move from Monaco in the summer of 2011.
His fine form has reportedly attracted the interest of a number of clubs including Arsenal, Barcelona, Chelsea and AC Milan.
Now it appears Manchester City have joined the already lengthy queue of potential suitors for the powerful Cameroon defender.
City boss Roberto Mancini is keen to strengthen his defence, with Joleon Lescott and Kolo Toure expected to leave the club at the end of the season.
N'Koulou remained coy when quizzed about any potential move away from the Stade Velodrome, but refused to rule out a potential exit.
"I am waiting to sign a new proposal from Marseille," he said. "I am not thinking about moving anywhere this winter, but you never know in football.
"I love Marseille, that is for sure and I am enjoying it here."