National Crime Agency (NCA) officers are issuing a warning to potential drug smugglers after a series of cannabis seizures were made from passengers flying into Birmingham International Airport.
Nine people have been arrested at the airport in the last two weeks, all carrying between 15 and 40 kilos of the drug in suitcases.
In total around 260 kilos have now been seized by Border Force, worth an estimated £750,000.
Five of the passengers had flown in on routes from Thailand, four had started their journeys in the United States.
All nine have been arrested on suspicion of smuggling class B drugs, questioned by the NCA and bailed pending further enquiries.
NCA investigators are now looking into each seizure, and looking at whether any of the cases might be linked.
NCA Branch Commander Mick Pope said: “Following this unusual amount of seizures in such a short space of time, law enforcement will undoubtedly be paying more attention to passengers coming into Birmingham on certain routes and stepping up checks.
“We are continuing to investigate the circumstances of each, but I want to make a direct appeal to anyone considering getting involved in transporting drugs to the UK. Think very carefully about the consequences of getting caught.
“In some of these cases passenger journeys have started in locations where cannabis may be legal, but that won’t make a difference when you arrive in the UK.
“Organised criminal gangs rely on couriers to bring illicit substances into the UK, their business models rely on it. Consequently those playing such a role face stiff jail sentences. It simply isn’t worth the risk.”