Manchester United are reportedly holding Real Madrid responsible for the failure to complete David de Gea's move to Santiago Bernabeu.
It is thought that the clubs had agreed a deal worth £29m for the sale of the Spanish goalkeeper, with Keylor Navas heading to Old Trafford as part of the arrangement.
However, it has been reported that the deal fell through at the last minute because La Liga did not receive the final paperwork needed to complete the deal on time for Monday evening's Spanish transfer deadline.
According to PA Sport, United have told them that they uploaded the correct documents to FIFA's Transfer Matching System before the 11pm deadline and they have a time-stamp from FIFA as proof.
United reportedly feel that Madrid failed to submit their paperwork in time and therefore should be blamed for the deal's collapse.
It is not yet known whether Madrid or United will appeal over the termination of the transfer.