10 ; International audience ; The distribution of magnetic moments in the iron-rich intermetallic compound Lu2Fe17 with Fe partly substituted by Ru has been investigated on Lu2Fe16.5Ru0.5 by using several techniques. The crystal structure and temperature evolution of the magnetic structure was studied using high-resolution and high-flux neutron powder diffractometers. In contrast to the parent Lu2Fe17 which transforms on cooling from an antiferromagnetic to a ferromagnetic state, Lu2Fe16.5Ru0.5 is an antiferromagnet (Néel temperature TN = 208 K) down to the lowest temperatures. The magnetic polarization at the lutetium L2,3 absorption edges, iron K and ruthenium L2 edges was studied by x-ray magnetic circular dichroism (XMCD) on a single crystal of Lu2Fe16.5Ru0.5 in a magnetic field of 3 T, i.e. above the field-induced metamagnetic transition. The Ru XMCD signal proves the existence of induced magnetic polarization parallel to the dominant Fe sublattice magnetization. A corresponding theoretical analysis in the framework of the Local Spin Density formalism is provided in order to discern the structural disorder effects and magnetism in the system.