(1)  The Secretary may retain in his or her custody a child who has been taken to attend a place or person under section 20 or a requirement made under that section if the Secretary considers –

(a) that there is a reasonable likelihood that the child is at risk; and

(b) that further assessment of the matter is warranted; and

(c) that –

(i) the assessment cannot properly proceed unless the child remains in the Secretary's custody; or

(ii) it is desirable that the child be protected while the matter is being assessed.

(2)  The Secretary's custody of a child under subsection (1) ends 120 hours after the time at which the child arrives at a place or person under section 20 or a requirement made under that section unless, before the end of that period, custody of the child has been granted to the Secretary under an assessment order.