The investigation was launched after the Canada Border Services Agency (CBSA) intercepted a shipment of cannabis destined for the UK.
Investigators later identified two containers which had 12 tonnes of cannabis stored in 1,200 boxes, in transit to Southampton Port.
South West Regional Organised Unit (SWROCU) then executed warrants at the three suspects’ homes in south Wales on 16 June.
All three suspects were arrested on suspicion of facilitating the importations and are currently in police custody.
UK government minister for migration and citizenship, Mike Tapp MP, described the seizure as “record-breaking” and said the importing of drugs to the UK was a “vile trade”.
