A man from Dublin's Blackrock and two British nationals were in garda custody last night after the biggest seizure of drugs in Ireland this year.
An estimated €7m worth of cannabis herb was found at Dublin Port in an operation involving gardaí and customs officers.
It is understood that a number of criminal gangs "clubbed together" to organise the shipment that arrived in a container from Spain.
The Blackrock man does not have a previous profile in terms of organised crime, sources said.
"Revenue Customs officers and members of An Garda Síochána attached to the Garda National Drugs and Organised Crime Bureau conducted an operation which resulted in the seizure of 352kg of herbal cannabis with an estimated value in excess of €7m," a garda spokesman said.
"The illegal drugs arrived in a container from Spain through Dublin Port.
"Three males, aged 31, 47 and 49, were subsequently arrested by gardaí and are currently detained at garda stations in Dublin city.
Revenue said: "The collaboration between both agencies was significant in the successful outcome of this operation."