  Popular models for the origin of gamma-ray bursts (GRBs) include short-lived
massive stars as the progenitors of the fireballs. Hence the redshift
distribution of GRBs should track the cosmic star formation rate of massive
stars accurately. A significant proportion of high-mass star formation activity
appears to occur in regions that are obscured from view in the optical waveband
by interstellar dust. The amount of dust-enshrouded star formation activity
taking place has been estimated by observing the thermal radiation from the
dust that has been heated by young stars in the far-infrared and submillimetre
wavebands. Here we discuss an alternative probe - the redshift distribution of
GRBs. GRBs are detectable at the highest redshifts, and because gamma rays are
not absorbed by dust, the redshift distribution of GRBs should therefore be
unaffected by dust extinction. At present the redshifts of GRBs can only be
determined from the associated optical transient emission; however, useful
information about the prevalence of dust-obscured star formation can also be
obtained from the ratio of GRBs with and without an associated optical
transient. Eight GRBs currently have spectroscopic redshifts. Once about a
hundred redshifts are known, the population of GRBs will provide an important
test of different models of the star formation history of the Universe.
