50. Any person required by regulation 18 to present a returned product, or ensure that it is presented, to the official veterinary surgeon at a border inspection post need permit the official veterinary surgeon, or an assistant appointed pursuant to regulation 6(1)(b) or 6(2)(c), to carry out a physical check on the returned product only if the official veterinary surgeon has reasonable grounds for believing —
(a)that these Regulations have not been, or are not being, complied with in relation to the returned product;
(b)that the returned product does not comply with the import conditions; or
(c)that the identity or destination of the returned product does not correspond with the information given on any relevant document.