From: Doornkoop
This Prisoner of War record for Diederik Johannes Claassen 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=19447&r=Diederik Johannes&s=Claassen&ref=
This set of Prisoner of War documents can be accessed online via the FamilySearch.org project by Clicking Here.