An experimental study was made on the production of recoil ions in collisions of C and Ne ions with Ne. Absolute values of the Nei+ recoil ion production cross section sigma i were measured. The plot of sigma i against i shows a shoulder at i=3 and 4 in the Neq+-Ne collisions, which becomes conspicuous at the incident energy of 100 keV amu-1. This phenomenon is ascribed to the contribution of transfer ionisation to the recoil ion production. The net ionisation cross section, sigma += Sigma i i sigma i, was compared with a theoretical prediction based on a classical scaling rule.