  We have studied the anomalous Hall effect (AHE) in strained thin films of the
frustrated antiferromagnet Mn$_{3}$NiN. The AHE does not follow the
conventional relationships with magnetization or longitudinal conductivity and
is enhanced relative to that expected from the magnetization in the
antiferromagnetic state below $T_{\mathrm{N}} = 260$\,K. This enhancement is
consistent with origins from the non-collinear antiferromagnetic structure, as
the latter is closely related to that found in Mn$_{3}$Ir and Mn$_{3}$Pt where
a large AHE is induced by the Berry curvature. As the Berry phase induced AHE
should scale with spin-orbit coupling, yet larger AHE may be found in other
members of the chemically flexible Mn$_{3}A$N structure.
