We have recently discovered five Lyman continuum leaking galaxies at z \sim 0.3 , selected for their compactness , intense star-formation , and high [ O iii ] \lambda 5007/ [ O ii ] \lambda 3727 ratio ( ) .
Here we derive their ionizing photon production efficiency , \xi _ { ion } , a fundamental quantity for inferring the number of photons available to reionize the Universe , for the first time for galaxies with confirmed strong Lyman continuum escape ( f _ { esc } \sim 6 - 13 % ) .
We find an ionizing photon production per unit UV luminosity , \xi _ { ion } , which is a factor 2–6 times higher than the canonical value when reported to their observed UV luminosity .
After correction for extinction this value is close to the canonical value .
The properties of our five Lyman continuum leakers are found to be very similar to those of the confirmed z = 3.218 leaker Ion2 from and very similar to those of typical star-forming galaxies at z \ga 6 .
Our results suggest that UV bright galaxies at high- z such as Lyman break galaxies can be Lyman continuum leakers and that their contribution to cosmic reionization may be underestimated .