  We have performed 31P nuclear magnetic resonance (NMR) experiments on the
filled skutterudite compound PrFe4P12 to investigate the exotic ordered phase
at low temperatures and low magnetic fields. Analysis of the NMR line splitting
in the ordered phase indicates that totally symmetric (\Gamma_1-type) staggered
magnetic multipoles are induced by magnetic fields. This is incompatible with
any type of quadrupole order at zero field. We conclude that the ordered phase
has broken translational symmetry with the wave vector Q=(1,0,0) but the Th
point symmetry at the Pr sites is not broken by the non-magnetic \Gamma_1-type
order parameter.
