When the minor is under eighteen, the public prosecutor must be informed from the start of the detention. Unless this is not possible, the minor must be assisted by his or her legal representative. The person being checked may only be held for the time strictly required to establish his or her identity. Detention may not exceed four hours, or eight hours in Mayotte, from the time of the check carried out pursuant to Article 78-2 and the public prosecutor may terminate it at any time. If the person questioned maintains his refusal to prove his identity or provides manifestly inaccurate identity details, the verification operations may give rise, after authorisation from the public prosecutor or investigating judge, to the taking of fingerprints or photographs where this is the only means of establishing the identity of the person concerned. The taking of fingerprints or photographs must be mentioned and specially justified in the report provided for below. The judicial police officer shall mention, in a report, the reasons justifying the control and the identity check, and the conditions under which the person was brought before him, informed of his rights and given the opportunity to exercise them. It specifies the day and time at which the check was carried out, the day and time at which the detention ended and the duration of the detention. This report is presented to the person concerned for signature. If the latter refuses to sign it, mention is made of the refusal and the reasons for it. The report is forwarded to the public prosecutor, a copy having been given to the person concerned in the case provided for in the following paragraph. If it is not followed in respect of the person who has been detained by any investigation or enforcement procedure addressed to the judicial authority, the identity check may not give rise to storage on files and the report and all documents relating to the check shall be destroyed within six months under the supervision of the public prosecutor. In the event of an investigation or enforcement procedure being addressed to the judicial authority and accompanied by continued police custody, the detained person must immediately be informed of his right to have the public prosecutor notified of the measure to which he is subject. The requirements listed in this article are imposed on pain of nullity.