The authors have measured magnetic diffuse elastic cross sections for the Mn_1-nZn_nF₂ system at 4.2K and for one composition at 25K. Neutron polarisation analysis with a time-of-flight technique was used to separate the magnetic elastic cross section. Most magnetic disturbance appears on next-nearest-neighbour manganese atoms to the Zn impurity and is greater than would be expected from Lovesey and Marshall's model of very dilute alloys (1966). The range of the disturbance increases at higher temperatures.