Real Madrid have reported Inter Milan to Fifa over an alleged illegal approach for midfielder Luka Modric.
The
32-year-old Croat, who captained his country to the World Cup final and
was named player of the tournament, has been linked with a move to
Serie A.Real president Florentino Perez said this month the only way Modric would leave was if his 750 million euro (£671m) release clause was met.
Real sold Cristiano Ronaldo to Juventus for £99.2m in July.
Inter told BBC Sport the complaint is "based on circumstantial evidence".
The Italian club said they have never had direct contact with the player and Fifa's investigation is at a preliminary stage.
The transfer window in Italy closes at 19:00 BST on Friday.
Modric, who joined Real from Tottenham in 2012, has won La Liga once and the Champions League four times.
Inter have qualified for the Champions League for the first time since 2011-12.