In the United Kingdom, the Fruit of the Poisonous Tree doctrine is not recognized. Illegally obtained evidence is admissible in UK courts of law. The Fruit of the Poisonous Tree doctrine (also known as the Derivative Evidence Doctrine) is a rule used in criminal law. It is a doctrine that extends the exclusionary rule to make evidence inadmissible in court if it was derived from evidence that was illegally obtained. As the metaphor suggests, if the evidential "tree" is tainted, so is its "fruit." This doctrine was established in the United States in 1920 in the decision delivered within the Silverthorne Lumber Company case.

The Silverthorne Lumber Co. case was a US Supreme Court Case in which Silverthorne attempted to evade paying taxes. Federal agents illegally seized tax books from Silverthorne and created copies of the records. The key issue was whether or not derivatives of illegal evidence were permissible in court. The ruling, delivered by Oliver Wendell Holmes, Jr., was that to permit derivatives would encourage police to circumvent the Fourth Amendment of US Constitution, so the illegal copied evidence was held tainted and inadmissible.

The term itself was actually first used by Justice Felix Frankfurter in the case of Nardone v. United States (1939). The doctrine is intended to strongly deter police officers and their departments from using illegal means to obtain evidence against any and all alleged suspects.

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