As RWA has pointed out, Piyare Jain and Gurmukh Singh claim
in the paper linked above to be published in Journal of Physics G in January 2007. See their self-promotion at the University at Buffalo: thanks to James O'Leary for his real insider corrections. A nuclear physics experiment with lead is claimed to have observed many axions decaying into electron-positron pairs. The axion lifetime should be a fraction of picosecond and the mass is around 7 MeV and 19 MeV (two different signals).
The only thing I can say is that it looks strange to me. The previous articles about axions were focusing on