Welcome to the new version of the Patents Manual. Please note there are changes to the numbering and sequence of the chapters and pages in the manual. You are encouraged to take the time to explore and familiarise yourself with this new structure. Oral Evidence

Date Published

Key Legislation: 

Patents Act:

  • ​​​​​​​s210 Commissioner's powers  
  • s210A Sanctions for non-compliance with Commissioner's requirements  

Patents Regulations:



Section 210 of the Patents Act provides authority for the Commissioner to summon witnesses and to take evidence under oath or affirmation for the purposes of the Act.

A witness may only appear before the Commissioner as a result of:

  • the Commissioner issuing a summons following a request by one of the parties;
  • the Commissioner issuing a summons of his or her own volition; or
  • the Commissioner directing that the witness may appear voluntarily.

The Commissioner will require or allow oral evidence only in exceptional circumstances.  Oral evidence is given under section 210 and is generally not considered to be evidence in support, in answer or in reply or further evidence regulated by Chapter 5 of the Patent Regulations.  Consequently a witness may, according to the terms of the summons or Commissioner’s direction appear for the purpose of providing evidence in chief or for cross-examination on evidence already provided in declaratory form.  If providing evidence in chief, the other party generally has the right to cross-examine the witness under oath.  In either case the witness may also be re-examined.

For more information on the Commissioner’s role in summonsing witnesses see 7.6 Production of Documents, Summonsing Witnesses.

Where a person does not comply with a summons without reasonable excuse, the Commissioner may take a number of actions under section 210A (see 7.6.6 Sanctions for Non-Compliance).



Receiving oral evidence on Oath or Affirmation

Section 210(b) of the Act specifically allows the Commissioner to take evidence on oath or affirmation.

The taking of evidence on oath is not confined to the Christian or any other specific religion. An oath may be taken in such form and with such ceremonies as the person taking it declares to be binding upon him or her. If the witness is of a mind that an oath would not be binding upon them, or if on religious considerations they cannot make an oath, the witness may make an affirmation.

The hearing officer must be assured that the witness to be examined fully understands the solemnity and sanctions inherent in the making of an oath or an affirmation.  

Certain evidence may be taken unsworn; e.g. from a child, or from a person doing no more than presenting a document in answer to a subpoena, or an advocate giving evidence of a compromise reached by the parties.



Swearing in

A person appearing before the Commissioner to give oral evidence will be sworn in using the standard forms of "oath" and "affirmation" used by the ACT Supreme Court.  These are as follows:


The oath must reflect the witness’s beliefs.  For example, a Christian would make the following oath holding a copy of the Bible in their right hand.  

"I swear by almighty God that the evidence I shall give shall be the truth, the whole truth and nothing but the truth."​​​​​​​


"I solemnly declare and affirm that the evidence I shall give shall be the truth, the whole truth and nothing but the truth."

The oath or affirmation is administered by an official of the Patent Office other than the hearing officer, for example the opposition officer.



Examination procedures for oral evidence

Examination in chief

A witness may provide oral evidence in chief in an opposition or other matter. If oral evidence-in-chief is given, leading questions are not normally permitted in that they suggest coaching, or that the evidence is being suggested by the advocate rather than being stated from the witness’s own knowledge.  In particular, questions that suggest the answer that the advocate wants, or assumes the existence of a fact yet to be proved are leading questions.  However, the following types of leading questions are generally permissible

  • undisputed introductory material, e.g. the "qualifications" of a witness in terms of name, address, occupation, academic and practical qualifications etc.;
  • material to bring the witness quickly to the subject in issue, i.e. come straight to undisputed facts such as date, time, place, etc;
  • questions that bring the witness quickly to a contradiction of what is alleged by the other party; and
  • jogging the witness's memory (subject to discretion).

The Commissioner cannot require a witness to answer questions which the witness would not be required to answer in a court of law i.e. evidence in respect of which the witness could claim privilege.


The fundamental difference between evidence-in-chief and cross-examination is that in cross examination leading questions may be put to the witness.  Cross-examination is directed to two objectives; firstly to test the credibility of the witness and the accuracy and the completeness of his statements, and secondly to weaken, destroy or qualify the case of the other party.

Except for the matter of credit of the witness, cross-examination must be relevant to the facts in issue and must be confined to the admissible evidence (it is not confined to matters raised in the evidence-in-chief).  Generally speaking, questions on the credibility of a witness relate to ambiguities in the language used; interests which throw doubts upon sincerity (whether conscious or not); factors which throw doubt on the accuracy of the evidence, and leave open other possible interpretations; and factors which may have affected or otherwise coloured the witness’s memory.

The distinction between cross-examination questioning that goes to the facts in issue, and that which goes to the credit of the witness, is sometimes difficult to assess.  The witness's credibility depends upon his or her knowledge of the facts, expertise, integrity, and veracity; and questions may be asked to investigate each and all of these.  In terms of credit, the questions need not be otherwise relevant to the facts in issue and may be founded upon hearsay.

While leading questions may be asked during cross-examination, normal exercise of discretion would not allow "trap" questions, "double-barrelled" questions or questions that are vague or tend to mislead.  Questions which are considered to be improper or offensive should not be allowed.

Questions which go to getting a contradiction of the evidence-in-chief should be put in such a manner that the witness has an opportunity to explain the contradiction.  Where a cross-examining party intends to later contradict a witness (e.g. by calling further evidence or by suggesting that the witness’s testimony can be otherwise explained) the witness should be given the opportunity in cross-examination to comment on the contradictory version.  (See the decision of the UK House of Lords in Browne v Dunn (1893) 6R 67 HL, which applies to cross-examination in Australia (Hunt J in Allied Pastoral Holdings Pty Ltd v Commissioner of Taxation [1983] NSWLR 1 at [16]).)


Whereas the purpose of cross-examination is to weaken or destroy the evidence-in-chief, the purpose of re-examination is to repair any such damage.  In general, no new facts may be introduced at this stage and the re-examination must confine itself to explanations of matter arising in cross-examination.  However, this is subject to the Commissioner’s discretion, e.g. when matters were unknown until this stage, or perhaps had been overlooked by the parties’ representatives.  Nevertheless, the exercise of such discretion is, in effect, a re-opening of evidence-in-chief.



Unfavourable and hostile witnesses

An “unfavourable” witness is one whose testimony does not advance the case of the party who called them, despite the witness’s best intentions (for example due to forgetfulness or a genuine change in their interpretation of what they saw).  A witness who is not willing to truthfully answer questions asked by the party which called them is termed a "hostile" witness.  In this situation, the party calling the witness may ask the hearing officer to determine that the witness falls into either of the above categories.

Where the hearing officer makes a declaration that a witness is either unfavourable or hostile, the calling party is entitled to ask leading questions (e.g. in relation to previous conflicting statements).

Note that a declaration of hostility requires a finding that the witness is unwilling to tell the truth - a conclusion that cannot be lightly reached.  The practical effect of such a declaration is to nullify the witness's testimony altogether.


Note: As the Commissioner is functioning as a Tribunal, it would only be in extreme circumstances that the Commissioner would contemplate making a declaration that a witness is either unfavourable or hostile.


Decisions influenced by a witness’s actions or demeanour

When a court or tribunal proposes to draw conclusions, on the basis of observations of the actions or demeanour of a witness, which would significantly influence the decision in a case, the court or tribunal is required to communicate to counsel that it may use the observations at a stage of the proceedings at which counsel can deal with them in a proper way.  A decision will be invalidated by the failure to do so in a timely manner, unless the observations could not possibly have made any difference. See Marelic v Comcare, [1993] FCA 599.




When a witness is under cross-examination, they should not be assisted in any of their answers.  When a hearing is adjourned mid-way through a cross-examination, an undertaking will be required that the witness will not consult with his or her legal advisers during the adjournment.

However, where the witness is closely associated with the conduct of the dispute (such as the actual inventor), the undertaking might be varied to allow their counsel to derive facts from them without suggesting what answers they should give in further cross examination.



Resolving objections during cross-examination

During the cross-examination process, it is quite likely that objections will be raised by one or other of the parties in respect of procedural matters, or to the questions asked.  In resolving such objections, hearing officers should bear in mind that, as a tribunal, they are there to determine the truth in the matter.  That is, when arbitrating on an objection, the hearing officer should generally prefer a result which will lead to assistance in determining the truth in the matter to one which does not.


Amended Reasons

Amended Reason Date Amended
Back to top