Mrs Justice Joanna Smith, who co-chaired the council's working group, told the Bond Solon conference that undisclosed AI use will invite searching cross-examination. A family court has already discounted a Copilot-assisted assessment.
Joanna Smith, interim deputy president of the business and property division of the High Court of England and Wales, has instructed expert witnesses to be transparent with the court and with solicitors about artificial intelligence use in their reports, Australasian Lawyer and Canadian Lawyer report, citing the Law Society Gazette. Speaking at the Bond Solon Expert Witness Conference, she warned that reports could face searching cross-examination if they fail to indicate AI use that "may directly or even indirectly generate or influence the content of your evidence".
The instruction follows a Civil Justice Council report, published last week by a working group Smith co-chaired, which recommends a rule requiring experts to disclose where AI was used to produce or inform a significant part of a report. The council wants the rule written into amendments of the guidance for the instruction of experts in civil claims, which dates from 2014. Smith said the declaration may need to cover the methodology used, confirmation that the AI use was appropriate, and exceptionally the tool itself.
Smith said the duties of independence, objectivity, transparency and professional competence "remain exactly the same as they were before the emergence of AI", and identified the key risk as "the erosion of independent judgment, the outsourcing of your opinions to an AI agent". She cited Cornwall Council v M & Ors [2026] EWFC 306, in which an independent social worker instructed as an expert used Microsoft Copilot in a parenting assessment and related reports; the judge found AI had influenced a significant part of the evidence and could not give it considerable weight.
She recommended that experts confirm on receiving instructions whether they may use AI, or whether intellectual property, data protection or regulatory compliance issues prevent it, and disclose their intended use to instructing solicitors even where the instructions are silent.
