  A cadmium tungstate crystal boule enriched in $^{116}$Cd to 82% with mass of
1868 g was grown by the low-thermal-gradient Czochralski technique. The
isotopic composition of cadmium and the trace contamination of the crystal were
estimated by High Resolution Inductively Coupled Plasma Mass-Spectrometry. The
crystal scintillators produced from the boule were subjected to
characterization that included measurements of transmittance and energy
resolution. A low background scintillation detector with two $^{116}$CdWO$_4$
crystal scintillators (586 g and 589 g) was developed. The detector was running
over 1727 h deep underground at the Gran Sasso National Laboratories of the
INFN (Italy), which allowed to estimate the radioactive contamination of the
enriched crystal scintillators. The radiopurity of a third $^{116}$CdWO$_4$
sample (326 g) was tested with the help of ultra-low background high purity
germanium $\gamma$ detector. Monte Carlo simulations of double $\beta$
processes in $^{116}$Cd were used to estimate the sensitivity of an experiment
to search for double $\beta$ decay of $^{116}$Cd.
