we consider hyper-kaehler manifolds of complex dimension 4 which are fibrations. it is known that the fibers are abelian varieties and the base is $\mathbb p^2$. we assume that the general fiber is isomorphic to a product of two elliptic curves. our result is that such a hyper-kaehler manifold is deformation equivalent to a hilbert scheme of two points on a k3 surface.