We perform a theoretical study of the J / ψ → ω (ϕ) K ∗ K ¯ + c. c. → ω (ϕ) K 0 π + K - reactions with the assumption that the f 1 (1285) is dynamically generated from a single channel K ∗ K ¯ + c. c interaction in the chiral unitary approach. Two peaks in the K 0 π + K - invariant mass distribution are observed, one clear peak locates at the f 1 (1285) nominal mass, the other peak locates at around 1420 MeV with about 70 MeV width. We conclude that the former peak is associated with the f 1 (1285) and the latter peak is not a genuine resonance but a manifestation of the kinematic effect in the higher energy region caused by the K ∗ K ¯ + c. c. decay mode of the f 1 (1285) . [ABSTRACT FROM AUTHOR]