In this paper, we investigate the propagation of a weak optical probe pulse in an f-deformed Bose–Einstein condensate of a gas with the Λ-type three-level atoms in the electromagnetically induced transparency regime. We use an f-deformed generalization of an effective two-level quantum model of the three-level Λ configuration in which Gardiner's phonon operators for Bose–Einstein condensates are deformed by an operator-valued function, , of the particle-number operator . By making use of the quantum approach of the angular momentum theory, we obtain the eigenvalues and eigenfunctions of the system up to a first-order approximation. We consider the collisions between the atoms as a special kind of f-deformation. The collision rate κ is regarded as the deformation parameter and light propagation in the deformed Bose–Einstein condensate is analysed. In particular, we show that the absorptive and dispersive properties of the deformed condensate can be controlled effectively by changing the deformation parameter κ and the total number of atoms. We find that by increasing the value of κ the group velocity of the probe pulse changes, through deformed condensate, from subluminal to superluminal.