4. For the purposes of section 33A(b) of the 2006 Act, a person serving with the police includes—
(a)a constable of the British Transport Police Force, any person serving with that Force and any person employed by the British Transport Police Authority;
(b)a member of the Civil Nuclear Constabulary, any person serving with that Constabulary and any person employed by the Civil Nuclear Police Authority;
(c)a member of the Ministry of Defence Police;
(d)a member of the staff of SOCA;
(e)an officer of Revenue and Customs, but only when acting in the exercise of enforcement functions;
(f)a general customs official and any other person exercising general customs functions under the authority of the Secretary of State or the Director of Border Revenue, but only when acting in the exercise of enforcement functions;
(g)a customs revenue official and any other person exercising customs revenue functions under the authority of the Director of Border Revenue, but only when acting in the exercise of enforcement functions;
(h)an immigration officer and an official of the Secretary of State exercising functions relating to asylum and immigration, but only when acting in the exercise of enforcement functions.