Santos make FIFA threat to Real Madrid over Neymar pre-contract rumours
There's claims that Neymar already has an agreement to join Real in January.
But Ribeiro told Sport: "Neymar has nothing signed. First because it is illegal. He has an active contract.
"It would be an illegality on the part of Madrid, I'm sure (Real president) Florentino Perez would not commit, because he could be reported to FIFA for incitement to negotiate a contracted player."