A constable in uniform may stop and detain a vehicle or vessel for the purpose of the exercise of a relevant power.

A vehicle or vessel may be detained under sub-paragraph (1) for so long as it is reasonably required for the purpose of the exercise of the power concerned.

The power concerned may be exercised either at the place where the vehicle or vessel was first detained or nearby.

In this paragraph, “vehicle” includes caravan (within the meaning of section 29(1) of the Caravan Sites and Control of Development Act 1960).