  Using the {\it off-shell} Noether current and potential we compute the
entropy for the AdS black holes in new massive gravity. For the non-extremal
BTZ black holes by implementing the so-called stretched horizon approach we
reproduce the correct expression for the horizon entropy. For the extremal
case, we adopt standard formalism in the AdS/CFT correspondence and reproduce
the corresponding entropy by computing the central extension term on the
asymptotic boundary of the near horizon geometry. We explicitly show the
invariance of the angular momentum along the radial direction for extremal as
well as non-extremal BTZ black holes in our model. Furthermore, we extend this
invariance for the black holes in new massive gravity coupled with a scalar
field, which correspond to the holographic renormalization group flow
trajectory of the dual field theory. This provides another realization for the
holographic c-theorem.
