Related Rule
Botswana
Practice Relating to Rule 128. Release and Return of Persons Deprived of Their Liberty
According to the Report on the Practice of Botswana, it is the opinio juris of Botswana that persons in the power of an adversary should be released as soon as the reasons for arrest or detention have ceased to exist. 
Report on the Practice of Botswana, 1998, Chapter 5.4.