2 The first set of access conditions is fulfilled if—
(a) there are reasonable grounds for believing—
(i) that [F879an indictable offenceF879] 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 [F880, 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);F880]
(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.