(1) Where the European Patent Office considers it necessary to hear the oral evidence of parties, witnesses or experts or to carry out an inspection, it shall make a decision to this end, setting out the investigation which it intends to carry out, relevant facts to be proved and the date, time and place of the investigation. If oral evidence of witnesses and experts is requested by a party, the decision of the European Patent Office shall determine the period of time within which the party filing the request must make known to the European Patent Office the names and addresses of the witnesses and experts whom it wishes to be heard.
(2)107 At least two months' notice of a summons issued to a party, witness or expert to give evidence shall be given unless they agree to a shorter period. The summons shall contain:
(a) an extract from the decision mentioned in paragraph 1, indicating in particular the date, time and place of the investigation ordered and stating the facts regarding which parties, witnesses and experts are to be heard;
(c) an indication that the party, witness or expert may request to be heard by the competent court of his country of residence and a requirement that he inform the European Patent Office within a time limit to be fixed by the Office whether he is prepared to appear before it.
(3) Before a party, witness or expert may be heard, he shall be informed that the European Patent Office may request the competent court in the country of residence of the person concerned to re-examine his evidence on oath or in an equally binding form.
(4) The parties may attend an investigation and may put relevant questions to the testifying parties, witnesses and experts.
107 Amended by decision of the Administrative Council of 10.06.1988 which entered into force on 01.10.1988 (OJ EPO 1988, 290 ff).