  Gromov and Lawson conjectured that a closed spin manifold M of dimension n
with fundamental group pi admits a metric with positive scalar curvature if and
only if an associated element in KO_n(B pi) vanishes. In this note we present
counter examples to the `if' part of this conjecture for groups pi which are
torsion free and whose classifying space is a manifold with negative curvature
(in the Alexandrov sense).
