Evidence and Disclosure

Beginning in the 1990s, changes in the threats against which we work and developments in the law have seen us becoming increasingly engaged in the criminal justice process.

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Security Service officers have been witnesses for the prosecution in a number of high profile criminal trials, and intelligence material has either been admitted in evidence or disclosed to the defence as "unused material" in a significant number of cases. This has occurred mostly in the context of our counter-terrorist and serious crime work.

The increased involvement of the Service in criminal proceedings means that, when planning and carrying out intelligence investigations that may lead to a prosecution, we keep in mind the requirements of both the law of evidence and the duty of disclosure.

Our officers, working closely with members of law enforcement agencies, ensure that operations are properly co-ordinated with a view to the possible use of the resulting intelligence as evidence in court. For these reasons, as well as to ensure proper internal controls and compliance with legal obligations under the Regulation of Investigatory Powers Act 2000 (RIPA), we keep detailed records of our operations, including all meetings with agents, eavesdropping, search and surveillance operations.

Judges have allowed staff to give evidence in criminal trials anonymously, including appearing behind screens. Arrangements correspond to those that have been made for undercover and specialist police officers and members of the special forces when giving evidence. The decision on these issues, however, rests with the judge in each case. Even where the judge makes an order for the screening and anonymity of Security Service witnesses, their evidence remains subject to cross-examination by the defence in the normal way.

As for relevant intelligence that is not used in evidence, the duty of prosecutors to disclose such "unused material" to the defence is set out in the Criminal Procedure and Investigations Act 1996.

Protecting sensitive information

The Act does however recognise that the duty of disclosure must accommodate the need to protect sensitive information, the disclosure of which could damage important aspects of the public interest, such as national security.

Accordingly, where an investigation leads to a prosecution, prosecuting Counsel considers our records and advises which of them are disclosable to the defence. If disclosure would cause real damage to the public interest by, for example, compromising the identity of an agent or a sensitive investigative technique, the prosecutor may apply to the judge for authority to withhold the material. Such applications take the form of a claim for public interest immunity (PII).

Claims for PII in relation to our material are made on the basis of a certificate signed by the Home Secretary. In deciding whether a claim is appropriate, the Home Secretary carries out a careful balancing exercise between the competing public interests in the due administration of justice and the protection of national security. This exercise takes account of detailed advice from prosecuting Counsel on the relevance of the material to the issues in the case.

If the Home Secretary considers that the balance comes down in favour of non-disclosure, a claim for PII will be made. But the decision on a PII claim is one for the judge alone: it is the courts, not the Service or the Government, that ultimately decide what must be disclosed in a particular case. If a claim is accepted, the judge will continue to keep the decision under review throughout the proceedings.

Special Immigration Appeals Commission (SIAC)

The use of intelligence material as evidence is not confined to criminal proceedings. In particular, such material is frequently admitted in proceedings before the Special Immigration Appeals Commission (SIAC), the court established in 1997 to hear appeals against deportation on national security grounds.

SIAC's jurisdiction was extended by the Anti-Terrorism, Crime and Security Act 2001, to cover appeals by individuals who are detained under that Act pending deportation as suspected international terrorists. The unique feature of SIAC is its procedure, which is designed to enable the court to take account of sensitive evidence, including sensitive intelligence material. Where evidence is not sensitive, SIAC sits in "open" session. The appellant and his/her lawyers may participate in open sessions in the normal way, and members of the public may attend the proceedings.

However, evidence that SIAC is satisfied must be withheld from the appellant in order to avoid damage to the public interest is heard in "closed" session. The appellant and his/her lawyers, and the public, are excluded from closed sessions, and the appellant's interests are represented instead by a "special advocate" drawn from a panel of security-cleared Counsel. The special advocate may make submissions and cross-examine witnesses in the same way as the appellant's own lawyer in open.

Security Service officers have given evidence in many of the SIAC appeals held to date, both in open session (when they are screened in order to protect their identities) and closed.