  A small fraction of candidate tidal disruption events (TDEs) show evidence of
powerful relativistic jets, which are particularly pronounced at radio
wavelengths, and likely contribute non-thermal emission at a wide range of
wavelengths. A non-thermal emission component can be diagnosed using linear
polarimetry, even when the total received light is dominated by emission from
an accretion disk or disk outflow. In this paper we present Very Large
Telescope (VLT) measurements of the linear polarisation of the optical light of
jetted TDE Swift J2058+0516. This is the second jetted TDE studied in this
manner, after Swift J1644+57. We find evidence of non-zero optical linear
polarisation, P_V ~ 8%, a level very similar to the near-infrared polarimetry
of Swift J1644+57. These detections provide an independent test of the emission
mechanisms of the multiwavelength emission of jetted tidal disruption events.
