  The nature and physical properties of asteroids, in particular those orbiting
in the near-Earth space, are of scientific interest and practical importance.
Exoplanet surveys can be excellent resources to detect asteroids, both already
known and new objects. This is due their similar observing requirements: large
fields of view, long sequences, and short cadence. If the targeted fields are
not located far from the ecliptic, many asteroids will cross occasionally the
field of view. We present two complementary methodologies to identify asteroids
serendipitously observed in large-area astronomical surveys. One methodology
focuses on detecting already known asteroids using the Virtual Observatory tool
SkyBoT, which predicts their positions and motions in the sky at a specific
epoch. The other methodology applies the ssos pipeline, which is able to
identify known and new asteroids based on their apparent motion. The
application of these methods to the 6.4 deg 2 of the sky covered by the
Wide-Field CAMera Transit Survey in the J-band is described. We identified 15
661 positions of 1 821 different asteroids. Of them, 182 are potential new
discoveries. A publicly accessible online, Virtual Observatory compliant
catalogue was created. We obtained the shapes and periods for five of our
asteroids from their light-curves built with additional photometry taken from
external archives. We demonstrated that our methodologies are robust and
reliable approaches to find, at zero cost of observing time, asteroids observed
by chance in astronomical surveys. Our future goal is to apply them to other
surveys with adequate temporal coverage.
