Duties of an expert
Produced in partnership with Hardwicke
Duties of an expert

The following Dispute Resolution guidance note Produced in partnership with Hardwicke provides comprehensive and up to date legal information covering:

  • Duties of an expert
  • Key principles
  • Overriding obligation to the court
  • Failure of experts to comply with their duties

Key principles

Civil Procedure Rule (CPR) 35.3 makes clear that an expert is under a duty to assist the court on matters within his or her area of expertise. That duty overrides any obligation to the party instructing him.

The classic statement of an expert’s duties is set down in the judgment of Cresswell J in National Justice Compania Naviera SA v Prudential Assurance Co (the Ikarian Reefer) [1993] 2 Lloyds Rep 68 (not reported by LexisNexis®):

  1. expert evidence should be, and should be seen to be, the independent product of the expert uninfluenced as to the form or content by the demands of litigation

  2. an expert witness should provide independent assistance to the court by way of an objective unbiased opinion in relation to matters within his expertise

  3. an expert witness should never take on the role of an advocate

  4. an expert should state the facts or assumptions upon which his opinion was based without omitting any consideration or material fact which could detract from his concluded opinion

  5. an expert witness should make clear when a question or issue falls outside the scope of his expertise

  6. if an expert’s opinion is not properly researched because he considers insufficient data is available, then, this must be stated with an indication that he opinion is, in such circumstances, no more than