The email that could prove Griezmann negotiated with Barcelona in March Atletico Madrid Atletico reportedly have it in their possession

Sevan Karian, one of Antoine Griezmann's representatives, reportedly sent an email to the player's sister Maud and his father Alain in March.

This email is said to have contained information on Barcelona's offer for the Frenchman, as well as a draft containing salary proposals.

This is according to El Mundo, who have had access to the email and who report that Atletico Madrid chief executive Miguel Angel Gil Marin also has a copy of the email.

This document could, therefore, be a key piece of evidence in Atletico Madrid's case against Barcelona.

The capital city side are claiming that Barcelona should have paid 200 million euros for Griezmann because this was the amount stated in his release clause before it dropped on July 1 to 120m euros, the figure the Catalan club ended up paying.

Their argument is that Barcelona were negotiating with their player before the release clause dropped, although the Blaugrana deny that a pre-contract agreement existed.