Brits in their 20s shipped 'tonnes of cannabis' to Liverpool from Marbella, Tarragona, Barcelona and Costa Blanca

Working closely with police in Spain after finding an arsenal of home-made bombs and 150 kilos of speed and five kilos of cannabis in the Liverpool property in March, officers from Merseyside have helped capture the last few members of the gang this week.

Most of the accused parties who carried out the spade-work for the smuggling operation were young British men aged between 22 and 25, living in upmarket neighbourhoods in Barcelona and Marbella (Málaga) and driving top-of-the-range cars – despite apparently not having jobs or any legally-registered trade.

Tonnes of cannabis were transported to the UK from Spain in lorries carrying consignments of bricks, and when the two ringleaders and their brother-in-law – whom the younger men worked for – were arrested, a shoebox containing €120,000 in cash was unearthed.

Another 18 people, mostly British and believed to be all male, were arrested after 12 properties in the provinces of Alicante, Málaga, Tarragona and Barcelona were raided.

Police seized 1,646 marijuana plants and 58 hash buds ready for transport.

Several cargoes of up to 400 kilos at a time had been shipped to the UK already.

The lorries were supposed to be carrying marble slabs, but were packed into boxes which in fact contained bricks along with the drugs to obtain a similar weight and avoid their being inspected.

Vehicles were loaded for transport at a warehouse in Roda de Bara (Tarragona province), where one of the gang lived and where the hash was packaged up for shipping.

CCTV cameras had been installed by the gang, who monitored them closely.

A total of 24 people have been arrested, including the first three in Liverpool in March.

Photograph by the National Police