A five-judge Bench of the Hon’ble Supreme Court categorically observed as under in Masalti vs. State of U.P., (1964) 8 SCR 133 …
“14. … There is no doubt that when a criminal court has to appreciate evidence given by witnesses who are partisan or interested, it has to be very careful in weighing such evidence. Whether or not there are discrepancies in the evidence; whether or not the evidence strikes the court as genuine; whether or not the story disclosed by the evidence is probable, are all matters which must be taken into account. But it would, we think, be unreasonable to contend that evidence given by witnesses should be discarded only on the ground that it is evidence of partisan or interested witnesses. Often enough, where factions prevail in villages and murders are committed as a result of enmity between such factions, criminal courts have to deal with evidence of a partisan type. The mechanical rejection of such evidence on the sole ground that it is partisan would invariably lead to failure of justice. No hardand-fast rule can be laid down as to how much evidence should be appreciated. Judicial approach has to be cautious in dealing with such evidence; but the plea that such evidence should be rejected because it is partisan cannot be accepted as correct.”
Supreme Court
Masalti v. State of U.P., (1964) 8 SCR 133 : AIR 1965 SC 202 : (1965) 1 Cri LJ 226