  ^{69,71}Ga NMR/NQR studies have been performed on a single crystal of the
transuranium superconductor PuRhGa_{5} with Tc ~ 9 K. We have observed a
^{69}Ga NQR line at ~29.15 MHz, and assigned it to the $4i$ Ga site using the
NMR results. The ^{69}Ga NQR spin-lattice relaxation rate 1/T_{1} shows no
coherence peak just below Tc, but obeys a T^{3} behavior below Tc. This result
strongly suggests that PuRhGa_{5} is an unconventional superconductor having an
anisotropic superconducting gap.
