  The rapidly rotating primary component of Regulus A system has been observed,
for the first time, using the technique of differential interferometry at high
spectral resolution. The observations have been performed across the
Br$_\gamma$ spectral line with the VLTI/AMBER focal instrument in high spectral
resolution mode (R $\approx$ 12000) at $\approx$ 80-130m (projected on the sky)
Auxiliary Telescopes triplet baseline configurations. We confirm, within the
uncertainties, the results previously obtained using the techniques of
classical long-baseline interferometry, although the question of anomalous
gravity darkening remains open for the future study.
