  We report on the polarization measure, obtained with IBIS on board INTEGRAL,
of the prompt emission of GRB 061122. Over an 8 s interval containing the
brightest part of the Gamma-Ray Burst we put a lower limit on its polarization
fraction of 60% at 68% c.l. and of 33% at 90% c.l. on the 250-800 keV energy
range.
  We performed late time optical and near infra-red imaging observations of the
GRB field using the Telescopio Nazionale Galileo (TNG), and the
Canada-France-Hawaii Telescope (CFHT). Our multi-band (ugrizYJHK) photometry
allowed us to identify the host galaxy of GRB 061122 and to build its SED.
Using a photometric redshift code we fitted these data, and derived the basic
properties of the galaxy, including its type and redshift, that we could
constrain to the interval [0.57, 2.10] at a 90% c.l., with a best fit value of
z=1.33.
  The polarization measurement in different energy bands, together with the
distance determination, allowed us to put the most stringent limit (xi <
3.4x10-16) to date to a possible Lorentz Invariance Violation based on the
vacuum birefringence effect, predicted by some quantum-gravity theories.
