  We present high sensitivity radio observations of the merging cluster A521,
at a mean redsfhit z=0.247. The observations were carried out with the GMRT at
610 MHz and cover a region of $\sim$1 square degree, with a sensitivity limit
of $1\sigma$ = 35 $\mu$Jy b$^{-1}$. The most relevant result of these
observations is the presence of a radio relic at the cluster periphery, at the
edge of a region where group infalling into the main cluster is taking place.
Thanks to the wealth of information available in the literature in the optical
and X-ray bands, a multi--band study of the relic and its surroundings was
performed. Our analysis is suggestive of a connection between this source and
the complex ongoing merger in the A521 region. The relic might be ``revived'
fossil radio plasma through adiabatic compression of the magnetic field or
shock re--acceleration due to the merger events. We also briefly discussed the
possibility that this source is the result of induced ram pressure stripping of
radio lobes associated with the nearby cluster radio galaxy J0454--1016a.
Allowing for the large uncertainties due to the small statistics, the number of
radio emitting early--type galaxies found in A521 is consistent with the
expectations from the standard radio luminosity function for local (z$\le$0.09)
cluster ellipticals.
