Angular distributions of K⁰ mesons produced in 1.15 GeV/c {\pi }^- reactions on carbon and lead targets, measured with the FOPI spectrometer at GSI Darmstadt, are not isotropic. The ratio of these angular distributions shows a strong forward--backward asymmetry, which might be understood as a result of the reabsorption of forward produced kaons in lead nuclei. This effect agrees with the results of IQMD transport model. A simple geometrical model developed in order to estimate the effect of the absorption allows to determine the kaon mean free path equal to about 4 fm.

PACS numbers: 25.80.Hp