From: Kwaaimansfontein
This Prisoner of War record for Nantes Sarel Van Heerden 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=5479&r=Nantes Sarel&s=Van Heerden&ref=
This set of Prisoner of War documents can be accessed online via the FamilySearch.org project by Clicking Here.