  We model the recently published kinematic data set for Leo I dSph galaxy by
fitting the solutions of the Jeans equations to the velocity dispersion and
kurtosis profiles measured from the data. We demonstrate that when the sample
is cleaned of interlopers the data are consistent with the assumption that mass
follows light and isotropic stellar orbits with no need for an extended dark
matter halo. Our interloper removal scheme does not clean the data of
contamination completely, as demonstrated by the rotation curve of Leo I. When
moving away from the centre of the dwarf, the rotation appears to be reversed.
We interpret this behaviour using the results of an N-body simulation of a
dwarf galaxy possessing some intrinsic rotation, orbiting in the Milky Way
potential and show that it can be reproduced if the galaxy is viewed almost
along the tidal tails so that the leading (background) tail contaminates the
western part of Leo I while the trailing (foreground) tail the eastern one. We
show that this configuration leads to a symmetric and Gaussian distribution of
line-of-sight velocities. The simulation is also applied to test our modelling
method on mock data sets. We demonstrate that when the data are cleaned of
interlopers and the fourth velocity moment is used the true parameters of the
dwarf are typically within 1 \sigma errors of the best-fitting parameters.
Restricting the fitting to the inner part of Leo I our best estimate for the
anisotropy is \beta = -0.2^{+0.3}_{-0.4} and the total mass M = (4.5 +/- 0.7) x
10^7 M_sun. The mass-to-light ratio including the errors in mass, brightness
and distance is M/L_V = 8.2 +/- 4.5 solar units.
