art 4
The functions conferred on a constable under sections 17 and 19 of the Crime (International Co-operation) Act 2003 may be exercised by— (a) a general customs official in relation to an offence, or to offences, which if committed in the UK would relate to a general customs matter; or (b) a customs revenue official in relation to an offence, or to offences, which if committed in the UK would relate to a customs revenue matter.