  The platinum channel (\nu_e or anti-\nu_e appearance) has been proposed at
neutrino factories as an additional channel that could help in lifting
degeneracies and improving sensitivities to neutrino oscillation parameters,
viz., \theta_{13}, \delta_{CP}, mass hierarchy, deviation of \theta_{23} from
maximality and its octant. This channel corresponds to \nu_\mu -> \nu_e (or the
corresponding anti-particle) oscillations of the initial neutrino flux, with
the subsequent detection of (positrons) electrons from charged current
interactions of the (anti-) \nu_e in the detector. For small values of
\theta_{13}, the dominant \nu_\mu \to \nu_\tau (or corresponding anti-particle)
oscillation results in this signal being swamped by electrons arising from the
leptonic decay of taus produced in charge-current interactions of \nu_\tau
(anti-\nu_\tau) with the detector. We examine for the first time the role of
this tau contamination to the electron events sample and find that it plays a
significant role in the platinum channel compared to other channels, not only
at high energy neutrino factories but surprisingly even at low energy neutrino
factories. Even when the platinum channel is considered in combination with
other channels such as the golden (muon appearance) or muon disappearance
channel, the tau contamination results in a loss in precision of the measured
parameters.
