Customs and Excise Management Act 1979

34 Power to prevent flight of aircraft

(1) If it appears to any officer or constable that an aircraft is intended or likely to depart for a destination outside the United Kingdom from—

(a) any place other than a customs and excise airport; or

(b) a customs and excise airport before clearance outwards is given,

he may give such instructions and take such steps by way of detention of the aircraft or otherwise as appear to him necessary in order to prevent the flight.

(2) Any person who contravenes any instructions given under subsection (1) above shall be liable on summary conviction to a penalty of £200, or to imprisonment for a term not exceeding 3 months, or to both.

(3) If an aircraft flies in contravention of any instruction given under subsection (1) above or notwithstanding any steps taken "to prevent the flight, the owner and the commander thereof shall, without prejudice to the liability of any other person under subsection (2) above, each be liable on summary conviction to a penalty of £200, or to imprisonment for a term not exceeding 3 months, or to both, unless he proves that the flight took place without his consent or connivance.