A senior Garda officer yesterday advised people renting warehouses to check out potential tenants who may be involved in the drugs business.

Three cannabis factories with plants reckoned to be worth more than €2m have been raided by gardaí.

Cannabis plants worth €5m have been seized as part of an ongoing nationwide anti-drugs operation.

Gardaí are continuing to question five people in connection with the discovery yesterday of three cannabis growing facilities in Dublin and Cavan.