The sequential contact transformation technique is applied to the vibrational-torsional-rotational dipole moment operator for a molecule containing a threefold symmetric internal rotor in order to be consistent with the transformed Hamiltonian to be used in the analysis of the spectra of the molecule. The detailed discussion is presented of various types of dipole moments and corresponding vibration-torsion-rotation transitions. The transition matrix elements of the transformed dipole moment operator are given for CH3OH-like molecule.