Sch 1 para 2
The first set of access conditions is fulfilled if— (a) there are reasonable grounds for believing— (i) that an indictable offence has been committed; (ii) that there is material which consists of special procedure material or includes special procedure material and does not also include excluded material on premises specified in the application , or on premises occupied or controlled by a person specified in the application (including all such premises on which there are reasonable grounds for believing that there is such material as it is reasonably practicable so to specify); (iii) that the material is likely to be of substantial value (whether by itself or together with other material) to the investigation in connection with which the application is made; and (iv) that the material is likely to be relevant evidence; (b) other methods of obtaining the material— (i) have been tried without success; or (ii) have not been tried because it appeared that they were bound to fail; and (c) it is in the public interest, having regard— (i) to the benefit likely to accrue to the investigation if the material is obtained; and (ii) to the circumstances under which the person in possession of the material holds it, that the material should be produced or that access to it should be given.