We show how to write an off-shell action for the SU(2)×U(1)
supersymmetric WZW model in terms of N=2 chiral and twisted chiral
multiplets. We discuss the N=4 supersymmetry of this model and exhibit the
N=4 superconformal current algebra. Finally, we show that the off-shell
formulation makes it possible to perform a duality transformation, which leads
to a supersymmetric sigma model on a manifold with a black hole type
singularity.Comment: 12 page