Sporting CP have reportedly filed a complaint to FIFA over Wolves' signing of Portugal goalkeeper Rui Patricio.
The two clubs previously agreed a fee of €18m, however a move was scuppered at the last minute, with Sporting CP and agent Jorge Mendes blaming each other for the breakdown.
So upset was Patricio that he cancelled his contract with Sporting in protest of the behaviour of then-president Bruno de Carvalho. Several other Sporting players followed suit by cancelling their contracts, which eventually led to Carvalho being ousted from the club.
The saga has now turned even more sour, with Portuguese newspaper A Bola (via Sport Witness) report that Sporting have made an official complaint to FIFA, and that they are demanding a €54m fee from Wolves.