The cannabis was discovered in a van in Camlough, south Armagh.
The accused, three of whom are from Birmingham and the fourth from County Wexford, were arrested on Thursday.
Newry Crown Court was told the investigation involved the PSNI, National Crime Agency (NCA) and Garda (Irish police).
The 167kg drugs shipment was tracked through Spain, England and Ireland, the court heard.
The accused are Chris Connaughton, 36, of St Patrick's Place, Enniscorthy, County Wexford, and Birmingham men Stephen Dainty, 53, of Pool Farm Road, Alcocks Green, Mark Fleetwood, 51, of Dingleside, Hall Green and Paul Green, 62, Weatherfield Road, Tysley.
A lawyer for Mr Connaughton, in whose van the drugs were found, said his client was the "least-part player" and had merely agreed to collect unknown items using his van for a "200 euros cash in hand job".
The court was told he parked the van at Damolly Retail Park in Newry, where it was picked up by "others". The drugs were then allegedly loaded on in Camlough.
Flight records were revealed of connections from Birmingham to Dublin and Alicante in Spain using the credit card of Mr Fleetwood.
A lawyer for Mr Fleetwood said that he was the "patsy" of unknown contraband, "the camouflage in all  this, used by others".
A district judge said he was satisfied there was a case against the co-accused in what he believed was a major drug operation crossing international boundaries.
"There has been a highly significant arrest involving drugs with evidence that the four defendants have played a part in a joint venture to conspire to bring drugs into this jurisdiction," the judge said.
"I am refusing bail on the fear that the accused may interfere with evidence gathering in what is a live investigation."
The four co-accused were remanded to appear via video link at Newry Magistrates' Court on 29 April.

Rose Morelli, 17, said it was "hugely distressing" to see the photo of Alex Elliot on the leaflet by the right-wing Fratelli d'Italia.
Gay rights activist group Arcigay alerted her after she posted it online.
Fratelli d'Italia tweeted an apology for its "improper" use of the photo.
Ms Morelli took the photo as part of an art project. She and Alex Elliot chose the image after being moved by the case of US teenager Leelah Alcorn who took her own life in December. Leelah was born a boy but wanted to live her life as a girl.
She is now taking legal action after her lawyer said Alex's image had been "misrepresented" and may have breached copyright issues.
Mr Elliot, 17, said: "After the tragedy of Leelah Alcorn we wanted to get out the message, 'that can't happen again', and that what happened, was in my opinion, so horribly grotesquely moving."
Ms Morelli said: "It struck me as hugely ironic at first but after I got over that initial sense of irony, it was hugely distressing.
"The last thing we ever wanted to do was inflict harm on the members of the LGBT community.
"To find out it was being used against them in such a malicious way was horrible."
Italian law does not currently legislate against crimes motivated by the sexual orientation or gender identity of the victims.
On its website, the Trentino branch of the Italian gay rights group, Arcigay, described Fratelli d'Italia's use of Ms Morelli's photo as "an insult".
Ms Morelli's Italian lawyer, Alexander Schuster, said he planned to bring a civil action against Fratelli d'Italia and claim for damages.
In a message on Twitter, Fratelli d'Italia said the use of the photo had been "improper".
It said: "We did not want to offend the memory of Leelah."
However, the party maintained that "it is right to campaign against gender teaching in school".
Fratelli d'Italia (Brothers of Italy) is currently opposing a civil partnership bill being debated by the Italian parliament. It is also known for its anti-immigration stance.
Four men have appeared in court charged with attempting to smuggle £800,000 of cannabis into Northern Ireland in pallets of orange juice.
[NEXT_CONCEPT]
A student from Bristol is taking legal action after a picture of her friend was "misrepresented" by an Italian political party campaigning against transgender education in schools.