Two men have been charged with fraudulently importing drugs after police seized herbal cannabis worth £1.3 million.
The PSNI said they believe an organised crime gang operating in Northern Ireland was behind the importation of the drug, which resulted in a seizure believed to be one of the biggest in the region in recent years.
Three pensioners were among six people arrested after the haul was found on a shipping pallet inside an industrial sized fuel tank at a property in Dromore, Co Down on Friday.
Detective Superintendent Bobby Singleton said: "Cannabis is the backbone of the drugs economy and it is a significant profit maker for organised crime groups.
"Along with the potential harmful effects that it can do to individuals the violence, intimidation and drug death that accompanies the drug trade in Northern Ireland means that taking this load off the street has made a significant contribution to keeping people safe."
The men, aged 32 and 37, have been charged with fraudulently importing Class B controlled drugs, possession of Class B controlled drugs and possession of Class B controlled drugs with intent to supply.
They are due to appear at Newry Magistrates' Court on Monday April 2.
Two women aged 68, another aged 42 and a man aged 72 have all been released on bail pending further inquiries.
The discovery was made during a joint operation by the Police Service of Northern Ireland, An Garda Siochana and Irish customs officials as part of the Cross Border Joint Agency Task Force, established under the Fresh Start Agreement.
It followed intelligence sharing by law enforcement agencies on both sides of the border.
The PSNI has previously said there are between 60 and 70 organised crime gangs in the drugs trade in Northern Ireland.
Investigations are continuing but police have ruled out paramilitary involvement at this stage.
An Garda Siochana Assistant Commissioner Barry O'Brien said: "I wish to commend all agencies involved in both jurisdictions which resulted in the seizure of a substantial quantity of controlled drugs.
"This demonstrates the practical application of the Cross Border Joint Agency Task Force."
PSNI Assistant Chief Constable Stephen Martin added: "Our thanks go to all those involved in this operation for their diligence and professionalism.
"Their combined hard work and dedication has gone a long way in helping us achieve our shared goal of keeping people safe."
Meanwhile, suspected cocaine, heroin and ketamine estimated at over 2.5 million euro was seized during a joint operation involving Gardai and customs officials at Dublin Port.