If N is a normal group with r as a subset, then N contains all the element of the form grg^{-1}, thus contains all the finite product of these blocks.
That is, Ar is contained in N, so the conclusion is true!
Hi,
The solution to this question was really minor - almost trivial - just didn't spot it for some reason. :-s Silly me!
Please feel free to delete this thread - it would GENUINELY be of no use to anyone.
Thanks x