Conformal supergravities as Chern-Simons theories revisited
  We propose a superfield method to construct off-shell actions for N-extended conformal supergravity theories in three space-time dimensions. It makes use of the superform technique to engineer supersymmetric invariants. The method is specifically applied to the case of N=1 conformal supergravity and provides a new realization for the actions of conformal and topologically massive supergravities. 
Sergei M. Kuzenko and Gabriele Tartaglino-Mazzucchelli
hep-th math-ph math.MP