N-type liquid encapsulated Czochralski (LEC) undoped InP wafers are annealed between 700 and 900 degrees C for different durations. From a large quantity of Hall measurement results, it is found that there is a Hall mobility distribution dependent on the carrier concentration of the annealed material. The lowest mobility is observed in the samples with concentration around similar to 10(10) cm(-3). In these samples carrier mobility increases with increasing temperature which is caused by nonuniformity. Combined with results of defect investigation in the annealed material, formation of defects and their nonuniform distribution are found to correlate with this mobility distribution. The formation of defect complexes is interpreted as a reason for the high mobility observed in annealed InP.