So I looked it up -
In an English criminal court, there is no automatic "fruit of the poisonous tree" doctrine. If foreign or domestic authorities searched a property without a warrant, the evidence is still prima facie (on the face of it) admissible if it is relevant to the crime.
? The Test for Fairness: Under Section 78 of the Police and Criminal Evidence Act 1984 (PACE), the defense must convince the judge that admitting the warrantless evidence would have such an adverse effect on the fairness of the proceedings that the court must exclude it.
? The Balancing Act: A UK judge will rarely exclude highly reliable physical evidence (like weapons, drugs, or stolen goods) just because a procedural rule or warrant requirement was breached. The court will balance the seriousness of the procedural breach against the gravity of the crime.
? The Comparison to Germany: German criminal procedure strictly protects the home under Article 13 of the Basic Law (Grundgesetz). If German authorities conduct a search without a judicial warrant (and without an immediate emergency or Gefahr im Verzug), German courts frequently issue a preservation/exclusionary ban (Beweisverwertungsverbot). An English court is not bound by this German constitutional exclusion and will apply the broader PACE fairness test instead.