As regards contracts which are illegal at common law the principal categories are:-
- transactions in things extra commercium, and
- contracts entered into with a fraudulent object (Weeramantry, pages 342 para 348).
As to things extra commercium, the Roman distinction between things absolutely extra commercium and things relatively extra commercium is recognised in modern Roman Dutch law. Some of the things absolutely extra commercium are the – (i) seashore, (ii) public streams, (iii) crown lands, (iv) minerals found thereon and public property. Amongst things relatively extra commercium are – opium, foreign currency, dangerous drugs and fire arms (for which a license is required).
As to fraud the classical statement is “Fraud is not a thing that can stand even when robed in a judgment” [Black on Judgments Vol. 1 section 292-293, cited by Bertram C.J., in Suppramaniam v. Erampakurukal, (1922) 23 NLR 417, 435, (FB)].
The most interesting aspect of Roman law is the Paulian Action, under which an alienation of property can be challenged, if it is fraudulent. In Roman law, it was a collective action. In modern Sri Lanka, it is an action brought by an individual creditor who challenges fraudulent transfer by the dobtor.