  For compact hyperbolic 3-manifolds we lift the Bloch invariant defined by
Neumann and Yang to an integral class in K_3(C) Applying the Borel and the
Bloch regulators, one gets back the volume and the Chern-Simons invariant of
the manifold. We also discuss the non-compact case, in which there appears a
Z/2-ambiguity.
