The Criminal Procedure and Investigations Act 1996 or CPIA [1] is a piece of statutory legislation in the United Kingdom that regulates the procedures of investigating and prosecution of criminal offences.

[2] It details the procedures for disclosure and continued disclosure by the prosecution to the defence any information "which is in the prosecutor’s possession, and came into his possession in connection with the case for the prosecution against the accused.

[2] The second part of the act defines a criminal investigation as "an investigation conducted by police officers with a view to it being ascertained whether a person should be charged with an offence, or whether a person charged with an offence is guilty of it."

[3] Section 54 of the act includes the follow administration of justice offences: In 2009, twenty six environmental protesters were pre-emptively arrested and later charged with conspiracy to commit aggravated trespass.

Non-disclosure to the Crown Prosecution Service and defence teams is a breach of the act.