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.