In T 1076/12 the board held that it was the text of the application as originally filed, even if the text was not in an official language of the EPO, that had to be used, together with any other non-text portions of the application as filed, in order to determine the "content of the earlier application as filed" as referred to in Art. 76(1) EPC.
Source: http://www.epo.org/law-practice/legal-texts/html/caselaw/2019/e/clr_ii_f_2_1_3.htm
Date retrieved: 17 May 2021