  Weak gravitational lensing is considered to be one of the most powerful tools
to study the mass and the mass distribution of galaxy clusters. However, the
mass-sheet degeneracy transformation has limited its success. We present a
novel method for a cluster mass reconstruction which combines weak and strong
lensing information on common scales and can, as a consequence, break the
mass-sheet degeneracy. We extend the weak lensing formalism to the inner parts
of the cluster and combine it with the constraints from multiple image systems.
We demonstrate the feasibility of the method with simulations, finding an
excellent agreement between the input and reconstructed mass also on scales
within and beyond the Einstein radius. Using a single multiple image system and
photometric redshift information of the background sources used for weak and
strong lensing analysis, we find that we are effectively able to break the
mass-sheet degeneracy, therefore removing one of the main limitations on
cluster mass estimates. We conclude that with high resolution (e.g. HST)
imaging data the method can more accurately reconstruct cluster masses and
their profiles than currently existing lensing techniques.
