In common law jurisdictions discovery is widely recognised as a “continuing obligation.” The same would apply in civil law jurisdictions: if a document that came to light post-discovery is perceived to be relevant and a party wanted to rely upon it, it would and should be produced and entered into the record albeit late (subject always to the right of the tribunal to exclude late evidence).
If document production has been undertaken pursuant to the IBA Rules the categories of document will be firstly, a document upon which a party wishes to rely and, secondly, those produced pursuant to a Request for Production which generally be those perceived to be helpful to another party. In light of a witness statement or expert report a party may realise that it has an additional document that it wishes to rely upon or the process of taking witness statements reveals that a witness has a document that a party wishes to use. In these circumstances the document should be produced to the other parties promptly. Any tactical withholding or delayed production is unlikely to be viewed favourably by the tribunal.
If a party has been obliged to produce documents pursuant to a Request to Produce and subsequently comes across a document that is responsive to the Request then, again, that should be produced promptly.
In each case a party producing documents late should tender an explanation for the delay consistent with the IBA obligation to undertake document production in good faith.
Article 3(11) of the IBA Rules recognises this concept that something relevant may come to light after the original round of document production but equally seeks to prevent abuse by permitting additional document production after documents produced by another party, witness statements, expert reports or the submissions of another party – but only within a defined time period.