In T 143/91 the board held that a member of an opposition division was biased if he had a personal interest within the meaning of Art. 24(1) EPC 1973. The mere fact that the member had previously been employed by a company dependent on a party to the opposition proceedings was, however, not sufficient proof of such an interest.

In R 12/09 of 3 December 2009 date: 2009-12-03 the petitioner objected to the members of the Enlarged Board in petition for review proceedings, alleging that they inevitably had a personal interest owing to their capacity as members of a technical board or the Legal Board of Appeal. The Enlarged Board rejected this objection as inadmissible (see in this chapter III.J.6.2.1).