The experimental 2π correlations in overlinepn → 2π +3π - annihilation at rest are studied as a function of the four-momentum transfer Q2. The distributions have maxima at Q2 = 0 GeV 2/c 2 with height h2 ∼ 4 for both 2 π+ and 2 π- correlations. This value is too high to be in agreement with the theory of the Bose-Einstein correlations. The experimental correlations are satisfactorily reproduced by the channel S 0(1390) π-, S 0(1390) being a 0 ++ state decaying ϱϱ and σσ. (σ is the S-wave, I = 0 ππ interaction.) The study of the predictions of this channel proves that the peak height is due to the contribution of two mechanisms having about the same strength: one is Bose-Einstein statistics, the other is the σσ- ϱ0ϱ0 interference. The 3 π- correlations are also reported and discussed.