Erling Haaland has included a release clause in his Manchester City contract which can be activated in two years' time.
Reports in Germany on Thursday claimed the figure for the release clause is £128million, but Sportsmail understands it is significantly higher than that.
City confirmed the £51m signing of Haaland from Borussia Dortmund earlier this week, beating a host of European rivals to his signature ahead of the summer transfer window.
After scoring 85 goals in 88 appearances for Dortmund, the 21-year-old striker had become one of the most sought-after players in world football, but City were quickest to pounce on the cut-price release clause which recently entered his contract.