Ajax insist Tottenham Hotspur target Urby Emanuelson will not be leaving the club in January.
The full-back's agent Brian Birkleef claimed earlier in the week that Spurs had been in touch regarding a potential deal.
Birkleef referred the matter to Ajax, who have stressed the 21-year-old will not be sold during next month's transfer window.
"Urby is a first-team regular at Ajax," technical director Martin van Geel told the club's official website.
Not under discussion
"We are short on defenders.
"Therefore, it is not under discussion to sell a player like Emanuelson during the winter break."
Spurs are also bereft of options in defence, with first-choice left-back Gareth Bale out for three months with a foot injury.
Ledley King, Ricardo Rocha and Anthony Gardner have been long-term absentees, while makeshift centre-half Didier Zokora is banned for the next three games.