  In this paper, we derive the analytical behavior of the limiting spectral
distribution of non-central covariance matrices of the "general
information-plus-noise" type, as studied in [14]. Through the equation defining
its Stieltjes transform, it is shown that the limiting distribution has a
continuous derivative away from zero, the derivative being analytic wherever it
is positive, and we show the determination criterion for its support. We also
extend the result in [14] to allow for all possible ratios of row to column of
the underlying random matrix.
