Comprehensive Repository
An extensive repository of expert witness decisions across all major common law jurisdictions, maintained as a working reference for practitioners and clients. For curated leading cases, see our Leading Cases overview.
Australia
Australian courts have developed a substantial body of jurisprudence governing expert evidence, informed by the Evidence Act 1995 (Cth), the Uniform Civil Procedure Rules, and the Expert Witness Code of Conduct adopted across federal and state jurisdictions.
Leading authority establishing the six-part test for admissibility of expert opinion evidence under section 79 of the Evidence Act 1995, requiring identification of specialised knowledge, basis of opinion, and clear disclosure of reasoning.
High Court decision clarifying that the admissibility of opinion evidence is determined by the requirements of the Evidence Act, not by divorced statements in case law; factual bases must be properly disclosed.
High Court landmark establishing that expert evidence not based on specialised knowledge is inadmissible; experts must clearly articulate the methodology and assumptions underlying their opinions.
Extensive consideration by Austin J of the admissibility and weight of expert evidence in commercial litigation, addressing the requirement for transparency in methodology and the consequences of adopting an advocacy role.
Court rejected expert evidence described as “little more than a partisan polemic,” establishing that evidence from blatantly partisan experts receives little or no weight.
Court of Appeal consideration of the requirements for expert reports to comply with the Expert Witness Code of Conduct and the consequences of non-compliance, including rejection or diminished weight.
Established fundamental principles for delay analysis methodology, holding that courts must examine actual evidence of what happened on site rather than relying solely on theoretical programming analysis.
Addressed the role and duties of construction experts in building defects litigation, including methodology for quantifying rectification costs and the standard of expert evidence in complex multi-party disputes.
Rejected expert report and oral evidence where solicitors who retained the expert had substantially written the report; established that genuine independence requires the expert to be the author of their own report.
Addressed the duty of expert witnesses to the court and the consequences of non-compliance with the Code of Conduct, including the potential exclusion of evidence and costs consequences.
Addressed the intersection of section 79 requirements with specialised proceedings; established that lack of proof of factual basis goes to weight, not admissibility of the opinion evidence.
Recent complex infrastructure case establishing standards for quantum expert evidence clarity, transparency, and alignment with recognised standards such as the SCL Protocol and EWI guidelines.
United Kingdom
The English courts have been at the forefront of developing the law relating to expert evidence, from the foundational principles in Ikarian Reefer to the reforms introduced by CPR Part 35.
Foundational authority establishing the duties of expert witnesses: overriding duty to the court, independence from litigation exigencies, impartiality, transparency in stating assumptions and facts, and obligation to consider material that detracts from conclusions.
Supreme Court decision abolishing the historical immunity of expert witnesses from suit for negligence, establishing that experts may be liable to their instructing party for breach of duty.
Supreme Court established the four-point test for admissibility of skilled evidence: whether it will assist the court, witness qualifications, impartiality, and whether there is a reliable body of knowledge supporting the evidence.
Confirmed that expert witnesses can be disciplined by professional bodies for seriously flawed evidence, particularly the misuse of statistics. Addressed the balance between encouraging participation and maintaining standards.
Jackson J’s extensive consideration of expert evidence in a major construction dispute; addressed methodology for delay analysis, duties of programming experts, and consequences of experts adopting partisan positions.
Addressed the preparation and presentation of quantum expert evidence in complex construction disputes, the methodology for assessing loss and expense claims, and the weight to be given to competing expert opinions.
Recent case reinforcing that CPR Part 35 and Practice Direction 35 must be satisfied, with drastic consequences for non-compliance including the court’s disregard of non-compliant expert evidence.
Court of Appeal authority on the duties of expert witnesses in construction proceedings, the standard of independence required, and the consequences of an expert’s failure to maintain requisite objectivity.
Recent TCC decision establishing that where a claimant controlled access to premises and could carry out exploratory investigations, it is reasonable to expect proof of claimed damage through expert evidence.
Established standards for expert evidence in financial matters, confirming that evidence meeting threshold tests can still be excluded if unhelpful, and that experts answering the “ultimate issue” does not destroy validity.
Hong Kong
The Hong Kong courts adopt principles consistent with the English common law tradition, supplemented by local practice directions governing expert evidence in construction and commercial disputes.
Court of Final Appeal authority on the duty of experts to the court, the requirement for independence from the instructing party, and the evidential consequences of a failure to maintain that independence.
Court of Appeal emphasised the high threshold for appellate interference with case management discretion on expert evidence directions; established that judges’ management decisions are rarely overturned.
Considered the role of construction experts in delay and disruption claims, the methodology for critical path analysis, and the weight to be accorded to programming expert evidence in Hong Kong proceedings.
Although an English authority, widely applied in Hong Kong proceedings. Addressed the obligations of expert witnesses instructed in international disputes and the consequences of non-disclosure.
Singapore
The Singapore courts have developed detailed rules governing expert evidence under Order 40A of the Rules of Court and the Evidence Act, with particular attention to the duties of experts in construction disputes.
Court of Appeal authority on the admissibility of expert opinion evidence under the Singapore Evidence Act, including the requirement that the expert possess relevant qualifications and that the opinion be based upon established methodology.
Addressed the duties and responsibilities of expert witnesses in Singapore proceedings, including the requirement for objectivity, the obligation to assist the court, and the consequences of evidence that amounts to advocacy.
Court of Appeal decision on the liability of expert witnesses for negligent testimony and the standard of care expected of experts instructed in commercial and construction litigation.
Canada
The Supreme Court of Canada has established a principled framework for the admissibility and assessment of expert evidence which is influential across common law jurisdictions.
Supreme Court landmark establishing the four-part test for expert evidence admissibility: relevance, necessity in assisting the trier of fact, absence of an exclusionary rule, and proper qualification of the expert witness.
Supreme Court authority establishing that lack of independence of an expert report can go to the threshold question of admissibility; confirmed that experts owe a special duty of impartiality to provide fair, objective, non-partisan assistance.
International Arbitration
International arbitration tribunals have developed their own approach to expert evidence, informed by the IBA Rules on the Taking of Evidence, the CIArb Protocol, and institutional practices.
Addressed the role of expert witnesses in international arbitration proceedings and the enforceability of arbitral awards where expert evidence is challenged on grounds of inadequacy or methodology.
Considered the standard of expert evidence required in international arbitration and the approach of the English courts to challenges to awards based on alleged deficiencies in expert testimony.
Addressed the treatment of quantum expert evidence in investment treaty arbitration, including the methodology for damages assessment and the weight to be given to competing valuations.
