  It is shown that there exists a truly marginal deformation of the direct sum
of two $G_k$ WZNW models at $k=-2c_V(G)$ (where $c_V(G)$ is the eigenvalue of
the quadratic Casimir operator in the adjoint representation of the group $G$)
which does not seem to fit the Chaudhuri-Schwartz criterion for truly marginal
perturbations. In addition, a continuous family of WZNW models is constructed.
