We present a multiwavelength study of the poor cluster RX J1117.4 + 0743 ( [ VMF 98 ] 097 ) at z = 0.485 , based on GMOS/Gemini South g ^ { \prime } , r ^ { \prime } photometry and spectroscopy , and XMM-Newton observations . We examine its nature and surroundings by analyzing the projected galaxy distribution , the galaxy velocity distribution , the weak-lensing mass reconstruction , and the X-ray spectroscopy and imaging . The cluster shows a complex morphology . It is composed by at least two structures along the line-of-sight , with velocity dispersions of 592 \pm 82 km s ^ { -1 } and 391 \pm 85 km s ^ { -1 } respectively . Other structures are also detected in X-ray , in the galaxy projected number density map , and by weak-lensing . One of these clumps , located East from the cluster center , could be gravitationally bound and associated to the main cluster . The derived temperature and bolometric X-ray luminosity reveal that [ VMF 98 ] 097 behave like a normal cluster , in agreement with L _ { X } - T _ { X } correlation found for both local ( z = 0 ) and moderate redshift ( z \sim 0.4 ) clusters . We find that the mass determination inferred from weak-lensing is in average 3 to 4.8 times higher ( depending on the model assumed ) than the X-ray mass . We have two possible explanations for this discrepancy : i ) the cluster is in non-equilibrium , then the deviation of the X-ray estimated mass from the true value can be as high as a factor of two ; ii ) the intervening mass along the line-of-sight of the cluster is producing an over-estimation of the weak-lensing mass . Based on the analysis presented , we conclude that [ VMF 98 ] 097 is a perturbed cluster with at least two substructures in velocity space and with other nearby structures at projected distances of about 1 h ^ { -1 } _ { 70 } Mpc . This cluster is an example of a poor cluster caught in the process of accreting sub-structures to become a rich cluster .