On the Ornstein-Zernike behaviour for the supercritical Random-Cluster model on ${\mathbb{Z}}^d,d\ge 3.$

We prove Ornstein-Zernike behaviour in every direction for finite connection functions of the random cluster model on ${\mathbb{Z}}^d,d\ge 3,$ for $q\ge 1,$ when occupation probabilities of the bonds are close to $1.$ Moreover, we prove that equi-decay surfaces are locally analytic, strictly convex, with positive Gaussian curvature.