  Performing Hamiltonian analysis of the massive gravity [9] in full phase
space, we see that the theory is ghost free. We also see in a more clear way
that this result is intrinsic of the interaction term and does not depend on
the variables involved. Since no first class constraint emerges, the theory
seems to lack gauge symmetry. We show that this is due to the presence of an
auxiliary field, and the symmetry may be manifest in the Stuckelberg
formulation. We give the generating functional of gauge transformation in this
model.
