Spitzer IRAC AGN selection criteria for the VLBI detected sample. The dashed line marks the region where a source is classified as an AGN by L07, the solid line is the revised AGN selection wedge by D12 and the dot-dashed line is the criterion used by K12. For all selection methods, AGN are those within the wedges in the top-right for all selection methods The solid line with black markers corresponds to the IR power law locus of Alonso-Herrero et al. (2006) in the range −3.0 ≤ α ≤ −0.5. Overlaid are the predicted SED colours of the ULIRG IRAS 22491, starburst galaxy M 82, AGN Mrk231, and an S0 galaxy from the SWIRE library (Polletta et al. 2007) across the same redshift range as the VLBI detections (z = 0 − 3.44). The perpendicular bars correspond to integer redshift intervals and open symbols correspond to the template MIR colours at z = 0. Left panel: VLBI-selected AGN colour coded by redshift, illustrating the large fraction of VLBI selected of AGN that are missed by the IRAC selection. Right panel: same VLBI-selected AGN sample instead plotted by host galaxy morphology.