In the general bipartite quantum system m ⊗ n, Wang et al. [Y.-L Wang et al., Phys. Rev. A 92, 032313 (2015)] presented 3(m + n) − 9 orthogonal product states which cannot be distinguished by local operations and classical communication (LOCC). In this paper, we aim to construct less locally indistinguishable orthogonal product states in m ⊗ n. First, in 3 ⊗ n(3 < n) quantum system, we construct 3n − 2 locally indistinguishable orthogonal product states which are not unextendible product bases. Then, for m ⊗ n(4 ≤ m ≤ n), we present 3n + m − 4 orthogonal product states which cannot be perfectly distinguished by LOCC. Finally, in the general bipartite quantum system m ⊗ n(3 ≤ m ≤ n), we show a smaller set with 2n − 1 orthogonal product states and prove that these states are LOCC indistinguishable using a very simple but quite effective method. All of the above results demonstrate the phenomenon of nonlocality without entanglement.