Expert evidence in inquiries

16th May 2023

In this next article in our series focusing on public inquiries, we look at the use of expert evidence in public inquiries.

There are two types of expert evidence to be considered within inquiry proceedings.

Firstly, section 11 of the 2005 Act allows ‘assessors’ to be appointed to provide technical advice to an inquiry. Either the minister setting up an inquiry (in consultation with the inquiry chair), or the inquiry chair, may appoint assessors. Assessors are expert advisers, appointed due to the expertise they hold, but they do not normally give formal evidence to an inquiry; instead, the role of an assessor is to provide assistance on specific issues to the inquiry panel as needed.

Secondly, more traditional expert evidence plays a crucial role in all public inquiries. An expert witness is a person who is called to give an opinion on matters which call for expert skill and knowledge. Their role is to provide technical analysis and expertise, which will assist the Inquiry in delivering its Terms of Reference. The evidence of an expert witness is public and a copy of their report will be published on an inquiry’s website and shared with the core participants to the inquiry.

Given that inquiries are generally tasked with considering a wide range of technical and specialist issues, the experts’ role is often key, providing an informed opinion on matters which call for expert skill and knowledge.

Expert witnesses are generally appointed by the chair to the inquiry, who will have considered the requirement for expert evidence taking into account the evidential picture as a whole. The chair can call for expert evidence at any point in the inquiry, as the picture develops.

Core participants can also instruct their own experts but require the chair’s permission to submit a report to the inquiry. Since it is the job of the inquiry to carry out any necessary investigation, permission will be granted only in exceptional circumstances.

The general expectations of an expert witness (in addition to any specific requirements set out) are that:

  • they must provide independent opinions confined to matters within their field;
  • owe the inquiry a duty to exercise reasonable care and skill;
  • must comply with any relevant professional code of ethics;
  • should take into account all relevant facts including any which might detract from their opinions and they should set out relevant facts and any literature or material upon which they rely;
  • should indicate whether any opinion they express is provisional or qualified and whether any additional information is required; and
  • should inform the inquiry if they change their opinion on any relevant matter.

Expert evidence can have a significant impact on the outcome of an inquiry, and it is therefore crucial that all participants consider carefully how the Inquiry is going to approach this issue, and keep this under review as the inquiry progresses.

Public inquiries series

In our series of blogs on public inquiries, we have also looked at:

Blake Morgan’s team of public inquiries solicitors have significant experience in representing clients in public inquiries.

If you need legal advice on public inquiries

Speak to one of our specialist lawyers

Arrange a call

Enjoy That? You Might Like These:


8 April -
Whether a school or academy trust, all who have contact with children have a duty to safeguard them. Senior leaders in the School and Academies sector, Designated Safeguarding Leads, SENCOs,... Read More


12 March
Are you ready for the change in procurement? To help, we are running a our series of webinars on the subject. In this webinar on Thursday 5 December, the focus... Read More


12 March
What are the social value opportunities under the Procurement Act 2023? We are running a series of webinars on the changes in procurement and in this webinar on Thursday 3... Read More