Evidence located abroad may be obtained through treaty mechanisms or, in some circumstances, through ordinary discovery directed at a party.
Parties. A party subject to the court’s jurisdiction may be ordered to produce documents in its possession, custody or control wherever located, subject to comity analysis where foreign law prohibits disclosure.
Non-parties abroad are generally beyond subpoena power, and the treaty route is the mechanism: a letter of request transmitted through a central authority, executed under the receiving state’s procedures.
The treaty is not exclusive. Courts weigh the importance of the documents, the specificity of the request, whether the information originated abroad, alternative means, and the interests of the states, in deciding whether to require treaty procedures first.
Limits of the treaty. Many states have objected to requests for pretrial discovery of documents, which restricts what can be obtained. Testimony is generally easier to obtain than broad document production.
Timing. Months to more than a year, which must be built into the schedule.
Assistance for foreign proceedings. A statutory mechanism permits application to a district court for discovery for use in a foreign proceeding, which is used extensively and has its own developing law on whether private arbitration qualifies.