Paris Saint-Germain have failed in an appeal to register the loan signing of Hakim Ziyech as Chelsea sent over the wrong paperwork to complete the deal three times.
The Morocco international spent the final day in the French capital as he tried to secure an exit from Stamford Bridge.
Everything appeared to be going smoothly and there was optimism that the deal would be completed before Tuesday’s deadline.
However, the move collapsed because the signature was not registered in time.
Reports in France that Chelsea were so fixated on signing Benfica’s Enzo Fernandez in a British record deal that they accidentally handed PSG the wrong paperwork three times, preventing the Ligue 1 giants from completing the required formalities.
PSG and Chelsea appealed the decision to the French football authorities, but this was rejected on Wednesday morning.
Ziyech had plenty of other suitors during the January window, including Newcastle United, Everton and Milan. The former Ajax side have also long been linked with a reunion.
But now he will stay at Chelsea at least until the summer.