Using the FS and HST versions of the free N = 4 matter multiplet (O4,(
1/2)4), we construct two N = 4 SU(2) conformal superfield models. The
corresponding N = 4 conserved currents are given. We find that no N =
4 SU(2) Liouville model exists as long as the SU(2) KM symmetry is man
ifestly preserved. However allowing an explicit breaking of the SU(2)
KM subsymmetry of the N = 4 conformal algebra down to U(1) KM, we obta
in & Feigin-Fuchs extension of the N = 4 supercurrent showing that N =
4 Liouville theory and its Toda generalizations could exist. Quantiza
tion and the N = 4 conformal anomaly are studied.