Article 20 Summoning of witnesses
(1)
Subject to rules 3 and 19(4) and paragraph (2) of this rule, the Tribunal may require any person to attend as a witness at any proceedings before the Tribunal and to answer any questions or produce any documents in his custody or under his control which relate to any matter in question in the appeal.
(2)
No person shall be required to travel more than 16 kilometres from his place of residence unless the necessary expenses of his attendance are paid or tendered to him.
(3)
Where a party requests the attendance of a witness, that party shall pay or tender those expenses.