Five people have been arrested after gardaí discovered the biggest cannabis grow house ever found in Ireland.

Officers from the Garda National Drugs Unit, along with local units in Meath, raided a shed in a rural area of Grange in Bective at about 2pm.

Gardaí found 1,720 cannabis plants compartmentalised at different growth stages – from incubation to drying - worth over €680,000.

220 of the plants were in a drying room ready for street sale within three days.

The grow house had sophisticated heat, light and irrigation systems powered by a large diesel generator.

Five men were arrested at the scene - four inside the shed and one waiting at a van.

Gardaí believe that the organised criminal gang producing the drugs is based in Finglas in Dublin.

It is the 28th grow house discovered since last July.