Impurity production and transport in ASDEX have been studied using a rotatable graphite collector probe which was exposed to the scrape-off layer plasma in the upper divertor chamber. Metallic deposits on the probe were later analysed using Rutherford backscattering spectroscopy and nuclear reaction analysis. Time resolved information (during tokamak discharges) and spatial profiles of collected impurity fluxes indicate strong erosion of the copper divertor plate during neutral beam heating of the plasma. Both stainless steel and copper deposits increase with neutral beam power. It is shown that, to a rough approximation, 0.2% of this auxiliary heating contributes to the increase in collected stainless steel impurities. Measurements made for single-null divertor discharges show that a copper flux of 6 × 10 17 atoms s −1 is present in the scape-off layer which is not directly sputtered from the target plates. Measurements made subsequent to boronization reveal an initial reduction in collected heavy impurities although boronization does not appear to have any significant long-term effect on the suppression of such impurities.