  The very first stars in the Universe can be very massive, up to
$10^6M_\odot$. They would leave behind massive black holes that could act as
seeds for growing super massive black holes of active galactic nuclei. Given
the anticipated fast rotation such stars would end their live as super massive
collapsars and drive powerful magnetically-dominated jets. In this paper we
investigate the possibility of observing the bursts of high-energy emission
similar to the Long Gamma Ray Bursts associated with normal collapsars. We show
that during the collapse of supercollapsars, the Blandford-Znajek mechanism can
produce jets as powerful as few$\times10^{51}$erg/s and release up to
$10^{56}$erg of the black hole rotational energy. Due to the higher intrinsic
time scale and higher redshift the initial bright phase of the burst can last
for about $10^5$ seconds whereas the central engine would remain active for
about 10 days. Due to the high redshift the burst spectrum is expected to be
soft, with the spectral energy distribution peaking at around 60keV. The peak
total flux density is relatively low, few$\times 10^{-7}erg\, cm^{-2} s^{-1}$,
but not prohibitive. The such events should be rear 0.03 year$^{-1}$, the
observations needs long term program and could be done in future.
