Procedure is that the crew check baggage in at SAA Ops. From there it goes directly to the aircraft. Upon arrival in London, The crew collect the baggage from the aircraft, take it to the bus and then depart via bus to the hotel. THE BUS MY OR MY NOT BE SELECTED FOR SEARCHING BY THE CUSTOMS OFFICIAL. this is how it is done for most of the foreign aircrew arriving in London. It is therefore almost 100% sure that somebody or more than one had to collect the "tampered bags" from the person Ls who did it and courier it knowingly to London...Very similar to the incident years ago in Cape Town. (Cape Town to London) The perpatrator was never brought to book although he was suspended with pay he was eventually dismissed (after more than 1,5 years)without appearing in court. Makes you think.