  Using SDSS I data, we have analysed the stellar distribution of the Leo II
dwarf spheroidal galaxy (distance of 233 kpc) to search for evidence of tidal
deformation. The existing SDSS photometric catalogue contains gaps in regions
of high stellar crowding, hence we filled the area at the centre of Leo II
using the DAOPHOT algorithm applied to the SDSS images. The combined
DAOPHOT-SDSS dataset contains three-filter photometry over a 4x4 square degree
region centred on Leo II. By defining a mask in three-filter colour-magnitude
space, we removed the majority of foreground field stars. We have measured the
following Leo II structural parameters: a core radius of r_c = 2.64 +/- 0.19
arcmin (178 +/- 13 pc), a tidal radius of r_t = 9.33 +/- 0.47 arcmin (632 +/-
32 pc) and a total V-band luminosity of L_V = (7.4 +/- 2.0) times 10^5 L_sun
(M_V = -9.9 +/- 0.3). Our comprehensive analysis of the Leo II structure did
not reveal any significant signs of tidal distortion. The internal structure of
this object contains only mild isophotal twisting. A small overdensity was
discovered appoximately 4.5 tidal radii from the Leo II centre, however we
conclude it is unlikely to be material tidally stripped from Leo II based on
its stellar population, and is most likely a foreground overdensity of stars.
Our results indicate that the influence of the Galactic graviational field on
the structure of Leo II has been relatively mild. We rederived the
mass-to-light ratio of this system using existing kinematic data combined with
our improved structural measurements, and favour the scenario in which Leo II
is strongly dominated by dark matter with (M/L)_V ~ 100 in solar units.
