The effect of this case is to put more obstacles in the way of the litigant who wants to secure disclosure.

In challenging a transfer of shares to the Bank after a rescue operation, the oil company’s request for disclosure of documents was opposed by the government. The House of Lords held that the documents, which concerned high-level policy, were not relevant to the case. The House, however, firmly rejected the argument based on candour as a reason for non-disclosure.

This decision makes it clear that even high-level policy documents might not be immune from disclosure.

C, a probationer police officer, sued a police superintendent for malicious prosecution. Crown privilege was claimed against a demand for the production of probation reports. The House of Lords allowed their production, there being nothing in the documents which was detrimental to the proper functioning of the police force or to the public interest.

Following this case a claim for PII is not conclusive of the issue. The court will inspect the documents and attempt to balance the public interest against disclosure with that of the interests of justice in disclosure. See Spencer and Spencer (2010).

A mother requested the identity of the person who had made a complaint to the NSPCC about her cruelty to her child. The allegation turned out to be baseless. The House of Lords stated that the public interest in the need for a flow of informers meant the disclosure should not be granted.

This case is an important illustration of the principle that authorised bodies as well as central government departments may claim PII.

A Royal Navy submarine sank on her maiden voyage in Liverpool Bay with the loss of 99 lives. The vessel had been commissioned by the Admiralty. Dependants of the civilian victims requested disclosure of official documents to assist their suit for damages against the ship owners. The government refused and the House of Lords held that the courts could not look behind a properly constituted claim for Crown privilege.

Although Conway v Rimmer overruled part of this judgment it is arguable that the courts will still not look behind claims made on the specific grounds of national security. Note, however, R (Mohamed) v Secretary of State for Foreign and Commonwealth Affairs (2010), where the Court of Appeal upheld the decision to disclose documents and refused the Foreign Secretary’s appeal.

The question arose in relation to potential proceedings against two chief constables and whether their documents created for the purpose of an investigation into the police under Part IX PACE were covered by class immunity. The House held there was here no compelling reason to create such a class immunity. There could, however, be a contents claim.

In Taylor v Anderton (1995) in another claim against the police the Court of Appeal accepted that there may be a class claim for a subset of documents dealing with the actual police reports on professional colleagues or members of the public.

M sued for malicious prosecution and sought discovery from the DPP of the identity of the person who had informed against him. The DPP’s refusal to disclose was upheld.

Most of the criminal cases involving PII concern police informers. The court recognised, however, that if disclosure was necessary to ensure a fair trial it should prevail.

K was charged with counterfeiting notes. He argued he had been tricked. The Court of Appeal upheld the decision to refuse to disclose the identity of the informant. The court set out the procedure for deciding on disclosure. It must examine the material and balance the public interest for and against disclosure. If the material may establish innocence, it must order disclosure.

In the subsequent case of R v Turner (1995) the Court of Appeal discussed the potential problem of defences being fabricated to obtain disclosure. Thus, the judge is required to hear details of the defence in any application.

An alleged drug dealer was watched from an observation point by police. At his trial he requested details of the post. The Court of Appeal refused.

The reasoning is analogous to that dealing with police informers and the same test for disclosure applied.

A mentally disturbed woman who fantasised about associating with the IRA had confessed to bombings she did not commit. Government scientists had withheld material on the basis that it might damage the prosecution case. The Court of Appeal held that this was an improper ground of PII.

This notorious miscarriage of justice case led to a change in the procedures for claiming PII in criminal cases. In R v Davis (1993) the Court of Appeal set out procedures for PII applications. The current rules are in the Criminal Procedure Rules 2020.