A man suspected by gardai of masterminding a network of lucrative cannabis growhouses has been arrested in a swoop by detectives.
The Chinese man has been a target of the garda national drugs unit for several months after it emerged he was a key player in the cannabis trade.
The network is alleged to have links to Triad gangs.
The 33-year-old suspect was detained, along with seven other men, as officers raided five growhouses in separate counties and seized 5,800 cannabis plants with a total estimated street value of €4.6m.
Six of the eight suspects are Asian and the others are English, although one has an address in Stradbally, Co Laois.
The Chinese kingpin, who was arrested during the search in Longford town, has been living in Lucan, Co Dublin. Officers from the national unit subsequently seized a computer and documentation, allegedly showing links between the five growhouses raided on Wednesday.
Since Operation Nitrogen was set up two years ago, around 60,000 cannabis plants, with an estimated street value of €46m, have now been seized.
During a search of an industrial unit at Connaught Road, Longford town, gardai found about 1,700 plants.
An industrial unit at Cornafulla, Athlone, Co Westmeath, an industrial premises in Drogheda business park, Co Louth, a commercial premises in Campile, Co Wexford, and an industrial unit at Kiltimagh, Co Mayo, were also raided.
All eight suspects are being held at garda stations around the country. Gardai said seven of the eight are suspected of acting as gardeners in the growhouses.
Officers believe that growhouse organisers are bringing people into the country from China and Vietnam to act as gardeners. Many agree to co-operate in the belief that their families are under threat from Triad members back home.
Meanwhile, in a separate operation, gardai from Finglas and Blanchardstown searched a premises at The Ward in north Co Dublin and discovered cannabis herb, cannabis resin and cocaine, with an estimated street value of €150,000.
There were no arrests, but inquiries are ongoing.
Two men were arrested following another unrelated find in Co Laois. Gardai discovered cannabis plants worth €20,000 in a growhouse at Ballyrider, near Stradbally.