Sussex Police’s West Sussex Tactical Enforcement Unit (TEU) carried out a proactive stop-check at a premises near Roundstone Lane, Angmering at 11.30am on Monday (9 November).
A cannabis cultivation site was discovered by officers and a large quantity of Class B drugs believed to have a street value of around £500,000 were seized.
Several men were arrested on suspicion of being concerned in the production of cannabis and remain in custody for questioning.
Enquiries are underway as officers work to establish the involvement of those arrested and of any additional suspects.
District Commander Chief Inspector Jon Carter said: “We work tirelessly to reduce harm in our local communities and would ask anyone with information or concerns to make the right call and report it to us.”
Anyone with information can report online or call 101, quoting 452 of 09/11.