  Rare decays of light mesons may be a discovery window for a new weakly
coupled forces hidden at low energy QCD scale. BES-III Collaboration reported
the observation of the rare decay $\eta'\rightarrow\pi^0\gamma\gamma$. The
observed decay width disagrees with the preliminary theoretical estimations. We
show that this tension may be attributed to the New Physics, presumably Dark
Photon.
  For completeness, we consider the possible influence of the New Physics on a
similar well-measured decay $\eta\rightarrow\pi^0\gamma\gamma$ and a recently
measured one $\eta' \rightarrow \eta\gamma\gamma$ and show that the impact of
the hypothetical Dark Photon may be also present in these decays also.
