Grounds for extensionU.K.
32(1)A judicial authority may issue a warrant of further detention only if satisfied that—
(a)there are reasonable grounds for believing that the further detention of the person to whom the application relates is necessary to obtain relevant evidence whether by questioning him or otherwise or to preserve relevant evidence, and
(b)the investigation in connection with which the person is detained is being conducted diligently and expeditiously.
(2)In sub-paragraph (1) “relevant evidence” means, in relation to the person to whom the application relates, evidence which—
(a)relates to his commission of an offence under any of the provisions mentioned in section 40(1)(a), or
(b)indicates that he is a person falling within section 40(1)(b).