Karthiyayani v Lee Liong Sin [1975] 1 MLJ 119 at p 120D-F:
If a witness is independent, ie, if he has no interest in the success or failure of a case and his evidence inspires confidence of the court, such evidence can be acted upon. A witness is normally to be considered independent unless he springs from sources which are likely to be tainted. If there are circumstances tending to affect his impartiality, such circumstances will have to be taken into account and the court will have to come to a decision having regard to such circumstances. The court must examine the evidence given by such witness very carefully and scrutinize all the infirmities in that evidence before deciding to act upon it.
