I had the same question and got this direct from CASA....
Subject: RE: Renewal of flight crew licence
Q. Having completed whatever refresher flying/theoretical training is necessary, could the BFR/AFR be done in UK? Either with a UK CAA Flight Examiner, or with an Australian CASA Flight Examiner living here in UK?
R. No, you have to do it in Australia. However, the CFI should take into account your flying recency in the UK. The instructor has to be either a Grade 1 or an approved Grade 2 employed by a CASA approved flight school (sorry).