6 Authorisation of directed surveillanceS
(1)Subject to the following provisions of this Act, the persons designated for the purposes of this section shall each have power to grant authorisations for the carrying out of directed surveillance.
(2)A person shall not grant an authorisation for the carrying out of directed surveillance unless that person is satisfied—
(a)that the authorisation is necessary on grounds falling within subsection (3) below; and
(b)that the authorised surveillance is proportionate to what is sought to be achieved by carrying it out.
(3)An authorisation is necessary on grounds falling within this subsection if it is necessary—
(a)for the purpose of preventing or detecting crime or of preventing disorder;
(b)in the interests of public safety; or
(c)for the purpose of protecting public health.
(4)The conduct that is authorised by an authorisation for the carrying out of directed surveillance is any conduct that—
(a)consists in the carrying out of directed surveillance of any such description as is specified in the authorisation; and
(b)is carried out in the circumstances described in the authorisation and for the purposes of the investigation or operation specified or described in the authorisation.