  We present a detailed spectroscopic study of the photoluminescence quenching
in an epitaxial structures containing CdSe/ZnSe quantum dots doped with low
concentration of Mn$^{2+}$ ions. Our time-resolved and time-integrated
experiments reveal the origin of the quenching observed in
macro-photoluminescence studies of ensembles of such dots. We show that
incorporation of even a few ions to an individual dot does not quench its
luminescence effectively, although some fingerprints of expected spin-dependent
quenching are visible. At the same time, the presence of Mn$^{2+}$ ions in the
sample significantly affects the luminescence intensity of the wetting layer,
resulting in a quenching of the global luminescence from studied structure. On
the other hand, the luminescence decay dynamics is found to be independent of
the presence of Mn$^{2+}$ ions, which suggests that the observed quenching
occurs for the excited excitonic states.
