The unconventional filled skutterudite superconductor, PrPt4Ge12 (Tc~7.9K), was recently discovered, for wihch zero field muon spin relaxation (ZF-MuSR) experiments reveal that time reversal symmetry (TRS) breaking occurs below Tc. ZF-MuSR experiments in the (Pr,La)Pt4Ge12 alloy series reveal that Pr-Pr intersite interactions are important for the booken TRS. Superconductivity was also discovered in partially filled skutterudite Pr0.5Pt4Ge12 (Tc ~ 7.66K), however specific heat measurements suggest that this is a conventional superconductor. We Propose to use ZF-MuSR to investigate how the TRS-breaking superconductivity of PrPt4Ge12 evolves with the Pr filled percentage.