  Electrical resistivity, specific heat and NMR measurements classify
non-centrosymmetric $\rm Mo_3Al_2C$ ($\beta$-Mn type, space group $P4_132$) as
a strong-coupled superconductor with $T_c = 9$~K deviating notably from
BCS-like behaviour. The absence of a Hebbel-Slichter peak, a power law
behaviour of the spin-lattice relaxation rate (from $^{27}$Al NMR), a $T^3$
temperature dependence of the specific heat and a pressure enhanced $T_c$
suggest unconventional superconductivity with a nodal structure of the
superconducting gap. Relativistic DFT calculations reveal a splitting of
degenerate electronic bands due to the asymmetric spin-orbit coupling,
favouring a mix of spin-singlet and spin triplet components in the
superconducting condensate, in absence of strong correlations among electrons.
