  In this note we examine the derivation of scale-dependent bias due to
primordial non-Gaussianity of the local type in the context of general
relativity. We justify the use of the Poisson equation in general relativistic
perturbation theory and thus the derivation of scale-dependent bias as a test
of primordial non-Gaussianity, using the spherical collapse model. The
corollary is that the form of scale-dependent bias does not receive general
relativistic corrections on scales larger than the Hubble radius. This leads to
a formally divergent correlation function for biased tracers of the mass
distribution which we discuss.
