From: Kaffirstad
This Prisoner of War record for Schalk Willem Jacobus Van Der Sandt was transcribed record from various documents held at the National Archives, South Africa, including arrest and shipping information from newspaper sources like De Zuid-Afrikaan.
https://www.gendatabase.com/boer-war-prisoner-record.php?q=14575&r=Schalk Willem Jacobus&s=Van Der Sandt&ref=
This set of Prisoner of War documents can be accessed online via the FamilySearch.org project by Clicking Here.