The static S(Q) liquid structure factors for binary FexNi100−x, x = 90 and 85 and ternary Fe85Ni5S10 molten alloys are investigated by means of the concurrent use of neutron diffraction and Reverse Monte Carlo simulations. The measured g(r) radial distributions reveal atomic orderings varying from that present in the Fe90Ni10 alloy, reminiscent of the ideal b.c.c. structure of solid Fe, to a far more open structure found in Fe85Ni5S10. From data at hand no clear evidence of clustering of sulphur within the Fe–Ni matrix is found but, in contrast, its addition leads to significant changes in structural properties manifested by the loss of the intermediate range order.