Absolute ratio of the maximum flux density of a Stokes V pixel, S _V,p, to the total flux density of a corresponding Stokes I source, S _I, as a function of angular distance from the LoTSS field pointing centre for sources with a Stokes I signal-to-noise ratio ⩾500. The top histogram shows the relative number of measurements with angular distance. We find a weak dependence of leakage with angular distance out to 3°. After ≈3° of angular distance, non-Gaussian noise and poorly calibrated facets account for the dependence.