Helium diffusion in Au60Ag40 is investigated using a variable energy positron beam. The positron diffusion length of the annealed material (66 +/- nm) is reduced after implantation of 2.2x10(14) He ions/cm(2) at 300 keV. During isochronal annealing up to 600 K, the recovery rate of the Doppler broadening lineshape parameter S strongly depends on the distance to the helium implantation peak, indicating an increase of the defect stabilization by He atoms. In contrast, for subsequent annealing, and irrespective of the depth, a maximum in S occurs at 670 K (around 0.5 T-m) resulting from competing processes of growth and breaking up of helium bubbles.