In a transfer saga that has rumbled on all summer, the German giants are desperate to clinch the deal before the transfer deadline on August 31.
On Tuesday, 23-year-old Martinez travelled to Munich to undergo his medical much to the lament of his La Liga club, who have now announced that he was not given permission to do so.
A message on their official website reads: "Athletic Bilbao want to make everyone aware that they haven't authorised the trip of player, Javi Martinez, to Munich on August 28. The club requests that explanations are provided by the player who remains theirs."
Negotiations between the two clubs have not run smoothly and despite the Bavarians' offer of 40 million euros for the player, the Basque side have still yet to agree on the fee.