The takeaway: The body that prosecutes crime in England and Wales put two AI-invented cases before the High Court — and they sat in the court file for eight months before anyone noticed. In a judgment handed down on Wednesday and picked up by the legal press today, Mr Justice Sweeting records that the Crown Prosecution Service cited two authorities that do not exist — Vlad v Romania and Jeziorski v Poland — in an extradition appeal, and that the CPS accepts they "were likely to have originated from the use of artificial intelligence". When the fictions finally surfaced, it was through database searches on both sides within days of each other — the CPS's own junior counsel first, then the defence independently. Nobody was sanctioned. The judge's verdict on the technology is the quotable part — and it cuts both ways.

Two cases that never existed

The underlying appeal, Tobosaru v Court of Law Craiolva, Romania [2026] EWHC 1720 (Admin) (the spelling is the court record's own), is routine extradition fare: two appellants challenging their surrender to Romania. What makes paragraphs 94–105 of the judgment anything but routine is how the requesting side's law got there. The CPS's grounds of opposition, filed in June 2025, cited Vlad v Romania [2017] EWHC 2060 (Admin); junior counsel's submissions days later added Jeziorski v Poland [2019] EWHC 3885 (Admin). Neither judgment exists. Both citations then quietly vanished from the skeleton argument filed on 2 February this year — with no explanation. Within days, database searches on both sides converged on the truth: the judgment records that junior counsel instructed for the CPS side had been unable to locate the authorities and raised the matter shortly before the appellants' team, who had searched, found nothing, and wrote to the CPS. The acknowledgement and apology followed within the week. Even the account of who spotted it first needed correcting — a CPS letter in March wrongly said counsel hadn't noticed until the defence raised it; a further letter in June corrected the sequence and apologised again.

The CPS's account, recorded in the judgment: the fabricated authorities likely originated from AI use, but "the reviewing lawyer did not properly check the accuracy of the document before it was filed and served" — the operative cause being "human error in the failure to verify the authorities". Senior managers then reviewed 78 other cases handled by the same lawyer and report finding no similar issues.

No harm done — this time, says the court

Sweeting J was explicit that the fictional cases changed nothing: they surfaced before the hearing and "had no impact on argument or the court's judgment". There was no referral for contempt or regulatory action; apologies and internal remediation were accepted. That leniency tracks the context — last year's Divisional Court ruling on fabricated citations reserved its sternest warnings for concealment and failure to own up, and here the CPS, however belatedly, investigated and owned the failure.

But the judge's closing observation is the line worth keeping: "It would be naive to assume that there will not be an increasing use of artificial intelligence in legal work in future; indeed, that may be both necessary and beneficial. The episode highlights the risks of its use without appropriate oversight particularly for legal research."

Why this one is different

Fabricated-citation stories are, by now, a genre — sanctioned solicitors, embarrassed barristers, a global tally of courtroom AI mishaps that grows weekly. This one is different because of who did it: not a struggling litigant-in-person or a cut-price firm, but the state's own prosecuting authority, in proceedings that decide whether people are handed to a foreign justice system. The mechanism is well understood — a language model asked for supporting authority will confidently invent one if a real one doesn't surface — which is exactly why every major piece of professional-conduct guidance since 2023 says the same thing: the tool may draft, but a human must check the law exists. For eight months, in the state's own filings against two people facing extradition, nobody had. The check that finally happened wasn't process — it was two lawyers, on opposite sides, typing a case name into a database and finding nothing there.