“(1) A party to whom a document has been disclosed may use the document only for the purpose of the proceedings in which it is disclosed except where - (a) the document has been read to or by the court, or referred to, at a hearing which has been held in public; (b) the court gives permission; or (c) the party who disclosed the document and the person to whom the document belongs agree.”
“16. Since 2001 the United Kingdom has become party to an increasing number of Conventions and bilateral and multi-lateral treaties which provide for international mutual legal assistance in criminal matters. These all contain provisions which restrict the use of evidence by the requesting state to the purpose specified in the request for assistance. Although these instruments post-date the decision in the BOC case, they illustrate the importance attached by the international community to such provisions forthe effective working of these schemes for mutual assistance. 17. The purpose and policy underlying such provisions is explained in a witness statement by Nicholas Vamos. He is the head of the United Kingdom Central Authority, which is the section within the Judicial Co-operation Unit of the Home Office responsible for mutual legal assistance in criminal matters. Provisions such as those referred to above provide the necessary guarantee that the material supplied will (i) only be used in criminal investigations and proceedings and (ii) only in the criminal investigations and proceedings specified in the request, unless the requested party consents to some wider use. Requests for assistance may involve the requested state using its powers of compulsion to gather and then forward sensitive or confidential information to the foreign requesting state. These provisions enable the requested state to retain an element of control over the material that it provides. 18. Restrictions on use ensure that states are not deterred from assisting each other in the prosecution of crime by the fear that material that they supply for one or more specified purposes might be used for other unrelated purposes. There may be legal issues under the national laws of the requested state (for example, relating to obligations of confidence) which would discourage or prevent the disclosure of material for the purposes of a criminal investigation, if it might then be used for other purposes, including civil litigation. 19. Mr Vamos says (para 39) that, if the United Kingdom were unable to give the guarantees and undertakings regarding collateral use required by some foreign states, there would be a reduction in the level of co-operation that they would be likely to provide. He also says (para 42) that, if the United Kingdom were unable to provide such guarantees and undertakings, it would be far more difficult for the United Kingdom to insist that such conditions were observed in relation to the evidence provided by it to its international partners. In short, these restrictions on collateral use of evidence provided by one state to another are necessary to ensure that the scheme of international mutual assistance in criminal matters works effectively. 20. This is the context in which the 1990 Act must be considered …”
“Nor can we believe that were we to allow this application, potential future witnesses would be deterred from co-operating in investigations yet to come or the police feel inhibited from giving future reassurance a to the consequences of such co-operation in the self-same terms as at present. That reassurance, be it noted, expressly admits of exceptions. What better case for an exception that this? And it is, moreover, a different case from those in which disclosure of this class of document is generally sought. The documents here are proposed for use not as a sword but as a shield: this is hardly a floodgate situation.”
“At the very lowest, the recently provided documentation could very well have filled the evidential gap that the judge perceived and as such may have led him to reach a different conclusion.”