The scope of discovery in proceedings in the United States is far wider than in any jurisdiction outside the U.S. Discovery is not confined to the parties to an action but extends, through the pre-trial procedure, to witnesses and potential witnesses in the action. They may be compelled to submit to oral examination and to produce documents if such procedure appears reasonably likely to lead to the discovery of admissible evidence, even though the information disclosed may not itself be admissible. Where discovery of this kind and scale is sought from non-U.S. nationals situated outside the U.S., conflicts are likely to arise between the extra-territorial jurisdiction asserted by the U.S. and the jurisdiction of the country or territory where the witnesses or potential witnesses are to be found.

The “letter rogatory” is one method whereby evidence may be obtained from abroad for use in U.S. proceedings. It is a formal communication in writing from the U.S. court before which an action is pending to a court in another jurisdiction, requesting that the testimony of a witness resident within the jurisdiction of the foreign court be formally taken under the direction of that court and transmitted to the U.S. court for use in the pending action.1 The extent to which effect will be given to letters rogatory in the English jurisdiction is now governed by the Evidence (Proceedings in Other Jurisdictions) Act 1975, which the House of Lords considered for the first time in the Westinghouse case.2 The Act replaces and repeals the Foreign Tribunals Evidence Act 1856 and gives effect in the U.K. to the 1970 Hague Convention on the Taking of Evidence Abroad in Civil or Commercial Matters.3 The speeches in the House of Lords emphasise that in giving effect to requests by foreign courts for assistance in obtaining the production of documents by non-party witnesses for use in civil proceedings abroad, the English court should adopt a restrictive approach, in particular where foreign anti-trust proceedings are concerned.