  Long ($>2$ s) gamma ray bursts (GRBs) are associated with explosions of
massive stars, although in three instances, supernovae (SNe) have not been
detected, despite deep observations. With new HI line and archival optical
integral field spectroscopy data, we characterize the interstellar medium (ISM)
of the host galaxy of one of these events, GRB 111005A, in order to shed light
on the unclear nature of these peculiar objects. We found that the atomic gas,
radio continuum, and rotational patterns are in general very smooth throughout
the galaxy, which does not indicate a recent gas inflow or outflow. There is
also no gas concentration around the GRB position. The ISM in this galaxy
differs from that in hosts of other GRBs and SNe, which may suggest that the
progenitor of GRB 111005A was not an explosion of a very massive star (e.g. a
compact object merger). However, there are subtle irregularities of the GRB
111005A host (most at a $2\sigma$ level), which may point to a weak gas inflow
or interaction. Since in the SE part of the host there is 15% more atomic gas
and twice less molecular gas than in NW part, the molecular gas fraction is
low. In the SE part there is also a region with very high H$\alpha$ equivalent
width. There is more continuum 1.4 GHz emission to the SE and an S-shaped warp
in the UV. Finally, there is also a low-metallicity region 3.5" (1 kpc) from
the GRB position. Two galaxies within 300 kpc or a past merger can be
responsible for these irregularities.
