Athletic Bilbao have released a statement saying Bayern Munich target Javi Martinez had no permission to travel to the German city yesterday.
The Spanish international was spotted in Munich, where he was thought to be undergoing a medical ahead of a €40m move to the Bundesliga club.
"Athletic Club wishes to state that it did not authorize the trip of the player Javier Martinez to Munich on August 28," read the notice on the club's website.
"In order to proceed as may be applicable, Athletic Club has requested appropriate explanations from the player, who belongs to their discipline."
Bilbao President Josu Urrutia has been loathe to let Martinez or teammate Fernando Llorente leave until their hefty release clauses are met.