A graph is d-polyhedral
provided it is isomorphic to the graph of a d-dimensional convex polytope. One of
the unsolved problems in the field of convex polytopes is to characterize
the d-polyhedral graphs for d > 3. There are, however, several necessary
conditions known for a graph to be d-polyhedral. In this paper we present a
new necessary condition which is not implied by the other conditions but
which has two of them as corollaries. We also show how this new condition
may be useful in solving problems dealing with ambiguity of d-polyhedral
graphs.