2.5.1 Sworn statements and affidavits

Article 117(1)(g) EPC provides for sworn statements in writing as a means of evidence (rare in practice). However, since any kind of evidence is admissible in proceedings before the EPO (long-standing principle confirmed many times, most recently in G 2/21), less solemn types of written statement (common in practice), e.g. statutory declarations, are also accepted. It is for the decision-making departments then to assess their probative value on a case-by-case basis. Such declarations consist of a witness's written statement, the main purpose of which is to avoid the need to hear that witness. The various departments may, however, decide to order such a hearing, for example if a party so requests. The terminology used in the case law of the boards of appeal includes "affidavits", "statutory declarations" and "unsworn statements" (French: "déclarations écrites", "déclarations sur l'honneur" and "attestations"; German: "eidesstattliche Versicherungen" and "eidesstattliche Erklärungen").

For further decisions dealing with unsworn declarations, see T 443/93, T 563/02. The board in French-language case T 2338/13 explicitly referred to affidavits as "attestations". The board in T 474/04 (OJ 2006, 129), which had English as the language of the proceedings, referred to a document entitled "eidesstattliche Versicherung" as a "declaration in lieu of an oath" and an "unsworn witness declaration". In T 703/12, the board called a document of this kind entitled "eidesstattliche Versicherung" a "statutory declaration" and in T 1231/11 an "affidavit". In proceedings before the EPO even a simple declaration can be an admissible means of evidence within the meaning of Art. 117(1) EPC (T 474/04, OJ 2006, 129).

The board in T 939/14 also held that the objection that affidavits did not meet the requirements of Art. 117(1)(g) EPC failed on the whole because standard board of appeal practice was to handle witness declarations, in whatever form or manner they are made, pursuant to the principle of free evaluation of the evidence. See also T 1117/16 above and T 41/19 below.

In R 3/10 the Enlarged Board took signed declarations of persons who had attended the oral proceedings into account.

In T 915/12 the board considered that there was not sufficient evidence to prove that D16 – an extract from the encyclopaedia – was made available to the public before the priority date (5 February 2001). The printing (2000) and copyright (1999) years indicated in D16 could not alone prove accessibility before early 2001. The hand-written annotation made by Ms S. – Head of Collections Department University – on the cover page did not fulfil the requirements of form and content which usually apply for affidavits or similar documents. However, see also T 649/20 regarding proof of the publication date of a scientific journal article. In this decision, it was discussed whether D1 (printouts of a journal database entry that only stated the year) should be considered prior art (available before the priority date – yes), particularly on the basis of a database extract from a medical library (document D14) submitted to establish the date the journal was received. Other evidence had been provided, including emails with the senior managing editor and the senior publisher; these two independent witness statements both gave the same date for the official publication date and the day the article went live. The board decided that D14 was already considered to provide sufficient evidence; the librarian that received and registered the journal in the database was a member of the public (see also T 834/09).