Distance-regular subgraphs in a distance-regular graph, II

Let Γ be a distance-regular graph with r = l(1, a1, b1), a1 > 0 and c2r+1 = 1. We show the existence of a collinearity graph of a Moore geometry of diameter r + 1 as a subgraph in Γ. In particular, we show that r = 1.