In the case of Olukade v Alade (1976) 2 SC 183, this Court summarised the general rule on the effect of the admission of inadmissible evidence:- “A court is expected in all proceedings before it to admit and act only on evidence which is admissible in law (i.e. under the Evidence Act or any other law or enactment relevant in any particular case or matter) and so if the court should inadvertently admit inadmissible evidence it has the duty not to act upon it.”
EVIDENCE GIVEN IN ANOTHER CASE, HOW MAY BE USED IN PRESENT CASE
Evidence given by a witness in another case may be used to impeach his credit if, in the later case, he says something different; but what he said in the earlier case does not become evidence in the later case. And a judgment given in another case can, in appropriate cases, be put in a later suit, to prevent the re-opening of the same question. One hopes that the indiscriminate introduction of other proceedings into a trial will be discontinued.
— Bairamian, F.J. Owonyin v. Omotosho (1961) – F.S.C.249/1960