PENAL CODE OF BOTSWANA
PART II Crimes
DIVISION II - OFFENCES AGAINST THE ADMINISTRATION OF LAWFUL AUTHORITY
Offences relating to the Administration of Justice (ss 111-123)
120. Conspiracy to defeat justice and interference with witnesses Any person who-
(a) conspires with any other person to accuse any person falsely of any crime or to do anything to obstruct, prevent, pervert, or defeat the course of justice;
(b) in order to obstruct the due course of justice, dissuades, hinders or prevents any person lawfully bound to appear and give evidence as a witness from so appearing and giving evidence, or endeavours to do so; or
(c) obstructs or in any way interferes with or knowingly prevents the execution of any legal process, civil or criminal, is guilty of an offence and is liable to imprisonment for a term not exceeding five years.
Offences against administration of justice
Conspiracy
Corruptly influencing a witness, obstructing or interfering with the attendance or testimony of a witness, retaliating against a witness for giving testimony or destroying, tampering with or interfering with the collection of evidence
EDIT.