Tottenham star Toby Alderweireld has a release clause of just €30 million (£25.4m), according to leaked documents.
Whistleblower website Football Leaks, cited by French outlet Le Soir, claims the centre-back can leave White Hart Lane if the clause in his contract is triggered.
The Belgian quickly established himself as one of the best defenders in the Premier League, alongside compatriot Jan Vertonghen in the centre of defence.
Le Soir have printed an extract of the player's contract stating the clause, while reports continue to circle claiming Tottenham are keen to tie Alderweireld down to an improved deal.
Vertonghen signed a new contract at Tottenham this past week, days after star striker Harry Kane penned new terms.
The pair are the latest in a growing list of Spurs players to recommit to the cause at White Hart Lane following last season's third-placed finish.
Dele Alli, Christian Eriksen, Eric Dier and Danny Rose have all also extended this season.