The information requested is not held centrally. UK officials and scientists would routinely have been present at a number of types of meetings and conferences, including those on the Biological and Toxin Weapons Convention, the negotiations leading to the Chemical Weapons Convention, chemical/biological defence and public health issues, at which South African counterparts may have been present. To identify each occasion where UK officials or scientists had contact with relevant South African counterparts would incur disproportionate cost.