Upper limit radio powers rescaled at 1.4 GHz vs. redshiftfor our ATCA observations (red triangles) and GMRTobservations Venturi et al. (2008) and Kale et al. (2013) (blue triangles). The lower (upper) border of the grey band corresponds to the lowest (highest) detection limit of injected fluxes, i.e. 3 mJy (5 mJy) for our ATCA images. The green and blue lines show the minimum power at 1.4 GHz of detectable radio haloes in the EMU survey as derived in Cassano et al. (2012).