A joint operation between Customs and Excise officers and Slough police uncovered the 175 kilos (27 stone 7 lbs) of herbal cannabis at the premises of a freight company in Colnbrook.

Detective constable Nigel Jones, of the drug enforcement team, said the freight company had no intentional involvement in the drugs shipment and had co-operated fully with police and customs throughout the operation.

He added: "We regard this large quantity of cannabis as a significant seizure.

"It may have been destined for sale in the Slough area or elsewhere but, wherever its intended market, we have caused considerable disruption to the suppliers and dealers."

The drugs were concealed in two pallets that were supposed to contain air filters.

The consignment was shipped from South Africa, via Tilbury Docks, and arrived at the warehouse in Colnbrook on Wednesday, 5 March.

Although a South African man made contact with the freight company, no-one appeared at the warehouse to collect the consignment.

Slough police are now continuing their investigations into the ownership and planned destination of the cannabis consignment.