Resumen
We investigate the degree of opacity of high-redshift galaxies to outgoing UV photons. Using multi-band images of high-redshift galaxies and HST photometry we show that in average no more than 4% of the continuum UV flux can escape (3 sigma limit) from each galaxy. This result is compatible with observations of low-redshift galaxies, but is in contradiction with some recent results based on spectroscopy of z ~ 3 galaxies.