  The aim of this work is to investigate the possible presence of extended
diffuse synchrotron radio emission associated with the intracluster medium of
the complex galaxy cluster A1689. The radio continuum emission of A1689 has
been investigated by analyzing archival observations at 1.2 and 1.4 GHz
obtained with the Very Large Array in different configurations. We report the
detection of an extended, diffuse, low-surface brightness radio emission
located in the central region of A1689. The surface brightness profile of the
diffuse emission at 1.2 GHz indicates a central radio brightness of ~1.7 \mu
Jy/arcsec^2 and the 3\sigma radio isophothes reveal the largest linear size to
be 730 kpc. Given its central location, the low-level surface brightness, and
the comparatively large extension, we classify the diffuse cluster-wide
emission in A1689 as a small radio halo.
