  We report the observation of spin-to-charge current conversion in strained
mercury telluride at room temperature, using spin pumping experiments. The
conversion rates are found to be very high, with inverse Edelstein lengths up
to 2.0 +/- 0.5 nm. The influence of the HgTe layer thickness on the conversion
efficiency has been studied, as well as the role of a HgCdTe barrier inserted
in-between the HgTe and NiFe layers. These measurements, associated to the
temperature dependence of the resistivity, allows to ascribe these high
conversion rates to the spin momentum locking property of HgTe surface states.
