investigation and attempt to discover the methods and techniques of investigation
used and the identities of agents and informants involved in the investigation.
The result could be to compromise methods and to deter, or even harm,
personnel used for the investigation of the subject and for other investigations.
That would undermine the effectiveness of the Security Service and its role in
safeguarding national security. There has been judicial recognition of the validity
of the reasons for the NCND policy: see paragraphs 46-54 of the Tribunal's
preliminary rulings in Applications Nos. IPT/01/62 and 77.

17. The certificate signed by the Secretary of State stated in a proviso to
paragraph 3:
"(i) no data shall be exempt from the provisions of s 7 (l)(a) of the Data
Protection Act 1998 if the Security Service, after considering any request
by a data subject for access to relevant personal data, determines that
adherence to the principle of neither confirming nor denying whether the
Security Service holds data about an individual is not required for the
purpose of safeguarding national security."

18. It was accepted by the Complainant that the NCND policy is not in itself
contrary to Article 8 or irrational and unlawful in every case. In some cases it is
accepted that it is justified as necessary. The complaint is that the NCND policy
ought not to have been invoked in the particular circumstances of this case

A. The Interference Issue

Select target paragraph3