It has been proved by Accola that any 3-fold unbranched
covering of a Riemann surface of genus two is hyperelliptic (a
2-fold branched covering of the 2-sphere) if the covering is non-
regular, and 1-hyperelliptic (a 2-fold branched covering of a torus)
if it is regular. In the present paper, we show that the corresponding result holds for closed 3-manifolds when replacing the genus
by the Heegaard genus.
