A 61-year-old man has been arrested and cannabis plants discovered in an underground bunker in the State’s north this morning.

The Tumbulgum man was arrested by police from the Tweed Byron Drug Unit who executed a search warrant on a rural property, about 15 kilometres west of Tweed Heads about 9.30am today.

The man was arrested as a part of an investigation into alleged ongoing drug supply in the local area.

While at the property, police located elaborate hydroponic cultivation equipment in a subterranean concrete bunker.

It will be alleged the bunker was built specifically for the cultivation of cannabis.

A large number of plants, in varying stages of maturity, have also been located. Police estimated the haul to be worth $1 million.

Inquiries are continuing.