Arc-transitive antipodal distance-regular covers of complete graphs related to SU3(q)SU3(q)

In this paper, we classify antipodal distance-regular graphs of diameter three that admit an arc-transitive action of SU3(q)SU3(q). In particular, we find a new infinite family of distance-regular antipodal rr-covers of a complete graph on q3+1q3+1 vertices, where qq is odd and rr is any divisor of q+1q+1 such that (q+1)∕r(q+1)∕r is odd. Further, we find several new constructions of arc-transitive antipodal distance-regular graphs of diameter three in case λ=μλ=μ.