Opium weighing approximately three-and-half kilos has been seized by the UK Border Agency at Dover.
The seizure was made on Wednesday (21 September 2011) when officers discovered the drugs, with an estimated street value of £50,000, hidden within a mixed load in an Iranian-registered lorry at the inward freight controls at Dover's Eastern Docks.
A 34-year-old man from Leeds has been bailed while enquiries into the attempted importation continue.
Carole Upshall, UK Border Agency Director for the south coast ports, said: "This is an excellent example of how UK Border Agency officers work tirelessly to detect and prevent drugs from being smuggled into the UK.
"We are determined to prevent this terrible trade which can have such a destructive impact on the lives of so many.
"Anyone with information about activity they suspect may be linked to drug smuggling should call our hotline on 0800 59 5000."
UK Border Agency officers use hi-tech search equipment to combat immigration crime and detect banned and restricted goods that smugglers attempt to bring into the country.
They also use an array of search techniques including sniffer dogs, carbon dioxide detectors, heartbeat monitors and scanners - as well as visual searches - to find well-hidden stowaways, illegal drugs, firearms and cigarettes which would otherwise end up causing harm to local people, businesses and communities.