B777 Captain reported rudder pedals were locked in position and would not move. Captain requested Maintenance inspect rudder pedal linkage and a rig pin was discovered still installed in the forward electronics and equipment bay.

Narrative

During the normal flight control check procedures after engine start for an MRO (Maintenance Repair Overhaul) FCF (Functional Check Flight) refly; the rudder pedals did not move and were locked in the neutral position. The First Officer also attempted to cycle the rudder pedals with the same locked in neutral results. We contacted the ground crew via radio to ensure the nose gear steering bypass pin was removed and steering bypass lever in normal steering position. The ground crew confirmed the nose gear steering bypass pin was removed and lever in the normal steering position. We performed an after landing checklist; performed shutdown and shutdown checklist. A maintenance representative opened the forward E&E door to inspect the flight control assembly area under the flight deck and found a rudder lockout/rig pin still installed then subsequently removed. I elected to have the aircraft towed back to the hangar to address how the rudder pedal rig pin was not removed after maintenance repair and needed confidence prior to future ops.Established maintenance procedures were not followed. [Suggest] ZZZ MRO Rig Pin Kit to better inventory parts.