Supreme Court Rules 2000

A party may interrogate any opposite party to obtain – an admission of any fact which the party interrogating is required to prove on an issue against the opposite party; or an answer as to – any fact directly in issue between the parties; or any fact, the existence or non-existence of which is relevant to the existence or non-existence of any fact directly in issue between the parties; or any fact, knowledge of which would inform the party interrogating of evidence of any fact directly in issue between the parties; or the name and address of any person who would be a necessary or proper party to the proceeding, if that information is required to make that person a party to the proceeding; or any other fact as to which discovery may have been obtained in a suit in equity before the commencement of the Act.

An interrogatory which does not relate to any matter in question in the proceeding is irrelevant, even though it might be admissible on the oral cross-examination of a witness.

This rule does not give a party the right to interrogate an opposite party with a view to finding out – a case for the party interrogating; or the name of any person intended to be called or who might be called by the opposite party as a witness and whose name is not a material fact in the proceeding; or the evidence of the opposite party; or the manner in which the opposite party intends to establish their case; or the line of facts, not being facts directly in issue, on which the opposite party intends to rely in support of their case; or the manner in which the opposite party intends to conduct the case at the trial.

The fact that a party who is otherwise bound to answer an interrogatory is not able to do so without disclosing the evidence or name of a person who might be called as a witness does not excuse the party from answering the interrogatory.