  Supermassive black holes (SMBH) are essential for the production of jets in
radio-loud active galactic nuclei (AGN). Theoretical models based on Blandford
& Znajek extract the rotational energy from a Kerr black hole, which could be
the case for NGC1052, to launch these jets. This requires magnetic fields of
the order of $10^3\,$G to $10^4\,$G. We imaged the vicinity of the SMBH of the
AGN NGC1052 with the Global Millimetre VLBI Array and found a bright and
compact central feature, smaller than 1.9 light days (100 Schwarzschild radii)
in radius. Interpreting this as a blend of the unresolved jet bases, we derive
the magnetic field at 1 Schwarzschild radius to lie between 200 G and ~80000 G
consistent with Blandford & Znajek models.
