[1] Pre-trial discovery is common between parties to an action that has already begun. It is less usual if the discovery is before the commencement of proceedings. It is even rarer still if the discovery is pre-action against non-parties to an intended action. The case of Norwich Pharmacal Co v. Customs and Excise Commissioners [1974] AC 133, was the watershed setting out the circumstances under which a pre-action discovery application may be made confining itself mainly to situations where it would be nigh impossible to commence an action against unknown defendants; unknown to the plaintiff but known to the party against whom a pre-action discovery is sought. As was observed by the Court of Appeal in Nishimatsu Construction Co Ltd v. Kecom Sdn Bhd; at p 103 [2009] 2 MLJ 404; [2008] 6 CLJ 149:

"Save in the circumstances set out in the decision of the House of Lords in Norwich Pharmacal Co v. Customs and Excise Commissioners [1974] AC 133, the Court has no jurisdiction to grant anticipatory discovery that is to say discovery in anticipation of the action being filed."

[2] The circumstances under which such an order may be made have since expanded to cover a variety