Real Madrid submitted the relevant paperwork for the transfer of Manchester United goalkeeper David de Gea 28 minutes past the European deadline, according to reports.
La Liga has confirmed that it did not receive the documents by the close of the transfer window in Spain at midnight (11pm BST) last night and according to Sky Sports News, it was Los Blancos who failed to complete the deal on time.
Manchester United claim that they sent all of their paperwork before the deadline and have the evidence to prove that their side of the transfer was complete.
According to Spanish newspaper Marca, the deal is off but could be resurrected in January.
It is not yet known whether Madrid or United will launch an appeal over the cause of the delay.
