The Supreme Court has held in Layade v. Panalpina (1996) 6 NWLR (Pt. 456) 544 at 558; (1996) 7 SCNJ 1 at 14-15 per Adio. J.S.C., as follows and I quote; ”The general rule is that where parties have embodied the terms of their agreement or contract in a written document, as it was done in this case, extrinsic evidence is not admissible to add to, vary, subtract from or contradict the terms of the written instrument … So, where the parties enter into a contract, they are bound by the terms of that contract and it is unfair to read into such a contract the terms on which there was no agreement.”
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