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The role of the expert in litigation

What is expert evidence?

The most recent report of the administrators in the reported Arena Television scandal refers to some of the investigations the administrators have been able to undertake. This includes their undertaking a forensic review of relevant bank statements. As the case against the directors (or other connected entities) in the High Court progresses, the court may decide it requires evidence from a forensic accountant. This is known as expert evidence.

Expert evidence is used to assist the court when the case before it involves matters on which it does not have the requisite technical or specialist knowledge. This means that the range of potential expert witness evidence is extremely broad reflecting the varied subject matter of legal disputes.

How are experts involved in cases?

There are two different ways in which an expert can be involved in a case and the distinction between them is important.

  1. an expert may be a court appointed witness (an expert witness).
  2. an expert may be an expert adviser (an expert whose role is to simply assist a party with their own case and whose acting can remain unknown to the court and the party’s opponent).

Expert witness

Where an expert is an expert witness the expert must provide independent assistance to the court by giving an objective opinion in relation to the matters upon which they have the expertise. The expert’s appointment and acting are governed by strict rules of court and their primary duty is to help the court. This duty overrides any duty which they may have to those who are instructing the expert.

Expert advisor

On the other hand, an expert adviser can assist a party with the formulation of their claim or defence. They can also advise a party on a particular specialist or technical matter within their expertise or provide appropriate advice in relation to strategy and settlement. Their duty is not to the court but to the party providing the instructions.

The court controls the giving of expert evidence (as opposed to expert advice). For example, it can decide if expert evidence is necessary, the amount and manner of the evidence and/or the fees of the expert that may be recoverable from the other party. The court may also decide that there should only be one expert witness who is instructed jointly by the parties. However, in complex cases the court is more likely to allow each party to instruct their own expert. In some cases multiple experts will be required to advise the court on different subjects.

Usually a report will be prepared by the expert witness in accordance with the court rules. All of the parties and the court have access to this report and the expert witness can be asked questions about it. Expert witnesses may also be required to give oral evidence at court at the trial itself.

Where each party has their own expert witness it is usual for the court to order that the experts discuss the case, reach agreement if possible and record what is agreed and what needs to be decided. After the discussion the experts will normally prepare a joint report which sets out the issues they agree and disagree (together with their reasons for disagreeing). On occasion it may be necessary for an expert to supplement their initial report.

Choosing an expert

Instructing the right expert at the right time must be given careful consideration. It is possible for an expert advisor to become an expert witness but it can give rise to difficulties. There is a risk that they will appear ‘tainted’ and no longer able capable of being independent. Any expert chosen must have a solid understanding of the court rules governing their evidence and the importance of independence: they must appreciate that they are not ‘hired guns’ for the party who is paying them.

In addition to being experienced and knowledgeable in their field of expertise, an expert witness should also be confident, clear, concise, credible, convincing and candid. It is a delicate balancing act to instruct an expert who has the requisite degree of specialism in their field but is also knowledgeable and experienced in the court process.


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Louise Goodwin


Advises companies and their owners/office holders, entrepreneurs and other individuals in respect of all private and commercial disputes encompassing injunctive proceedings and all forms of alternative dispute resolution.
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