It's shown through the Janus cosmological model framework that the object responsible for the phenomenon called "dipole repeller" is a spheroidal cluster made exclusively with anti-hydrogen and anti-helium of dark matter of negative mass. Emitting photons of negative energy, this object is not observable with optical instruments, but it plays a crucial role in the structure of the world of negative dark matters which contains neither galaxies, nor stars, nor heavy elements, nor planets, nor biomolecules. This model thus proposes an important extension of the theory of dark matter by including the existence of negative masses in the universe, and thus opens up new perspectives for understanding the structure and evolution of the universe as a whole.