Though the deal was initially reported to cost £230,000 for the 15 year old, that figure could be as high as £670,000. But Feyernoord are not happy with Chelsea's conduct.
The controversy is based around allegations that agents were used in the deal. This is illegal for under 16's in the Netherlands, and has become a political as well as sporting issue as politicians and Dutch football officials alike are demanding answers.
There is no doubt that Chelsea's long term game plan is to sign the most promising young talent and train them in one of the best Academies in the world. Yet it appears the controversy involved with signing teenagers for vast amounts of money is not going to end anytime soon for the club.