  We take advantage of the capabilities of the OTELO survey to select and study
the AGN population in the field. We performed an analysis of the properties of
these objects, including their demography, morphology, and IR luminosity.
Focusing on the population of H$\alpha$ emitters at $z \sim 0.4$, we also aim
to study the environments of AGN and non-AGN galaxies at that redshift. We make
use of the multiwavelength catalog of objects in the field compiled by the
OTELO survey, unique in terms of minimum line flux and equivalent width. The
OTELO pseudo-spectra allow the identification of emission lines and the
spectral classification of the sources. We obtained a sample of 72 AGNs in the
field of OTELO, selected with four different methods in the optical, X-rays,
and mid-infrared bands. We find that using X-rays is the most efficient way to
select AGNs. An analysis was performed on the AGN population of OTELO in order
to characterize its members. At $z \sim 0.4$, we find that up to 26\% of our
H$\alpha$ emitters are AGNs. At that redshift, AGNs are found in identical
environments to non-AGNs, although they represent the most clustered group when
compared to passive and star-forming galaxies. The majority of our AGNs at any
redshift were classified as late-type galaxies, including a 16\% proportion of
irregulars. Another 16\% of AGNs show signs of interactions or mergers.
Regarding the infrared luminosity, we are able to recover all the luminous
infrared galaxies (LIRGs) in the field of OTELO up to $z\sim 1.6$. We find that
the proportion of LIRGs and ultra-luminous infrared galaxies (ULIRGs) is higher
among the AGN population, and that ULIRGs show a higher fraction of AGNs than
LIRGs.
