Arc transitive distance regular covers of cliques

It is consider edge-symmetric distance-regular graph Γ with intersection array {k,(r−1)μ,1;1,μ,k}. Let G=Aut(Γ). Then G acts two-transitively on the set Σ of antipodal classes (fibres) of Γ. This graphs are classified in the next cases: 1) r=2 or r=k, 2) λ=μ, 3) G contains abelian normal subgroup N regular on Σ (affine case).