(1)For the purposes of sections 7(4), 11(3)(b) and 13(2), the test is that—
(a)there are reasonable grounds for suspecting that the person has committed an offence, and
(b)keeping the person in custody is necessary and proportionate for the purposes of bringing the person before a court or otherwise dealing with the person in accordance with the law.
(2)Without prejudice to the generality of subsection (1)(b), in considering what is necessary and proportionate for the purpose mentioned in that subsection regard may be had to—
(a)whether the person’s presence is reasonably required to enable the offence to be investigated fully,
(b)whether the person (if liberated) would be likely to interfere with witnesses or evidence, or otherwise obstruct the course of justice,
(c)the nature and seriousness of the offence.