Adrien Silva's move from Sporting CP to Leicester City remains in limbo after FIFA confirmed it had been contacted by the Football Association (FA) in relation to registering the player.
Reports emerged on Wednesday suggesting Silva's move had been held up after the Premier League club missed the deadline to register him by 14 seconds.
When contacted by Omnisport, a spokesperson for the world governing body responded: "We can confirm that FIFA has been contacted by the Football Association in connection with the registration of the player Adrien Silva and the club FC Leicester City.
"FIFA has replied accordingly providing reference to applicable regulations."
It remains unclear whether the Foxes will look to complete the reported £22million deal if they are unable to register Silva until the next transfer window in January.
Silva has started three league games for table-topping Sporting this season, also helping the team book a place in the group stage of the Champions League with a play-off win over Steaua Bucharest.
The Euro 2016 winner was set to be Leicester's replacement for England international Danny Drinkwater, who moved to Chelsea last month.
The FA was not immediately available for comment when contacted by Omnisport.