The Sun reports

Cops seized an estimated £1million of drugs in its tunnels and have yet to chart the full size.

A huge drugs factory has been found in a disused quarry in Wiltshire. Police are still studying the full extent of the maze of tunnels

Two beds were inside, and two Albanians held in yesterday’s swoop.

The set-up echoes TV’s Breaking Bad where drug kingpin Walter White ran a lab underground.

Sources say the farm at Bethel Quarry near Bradford-on-Avon, Wilts, could dwarf the previous biggest, found 26 miles away at the former Chilmark nuclear bunker last year.

Three men were jailed after cops found 4,425 plants in 20 rooms with the potential to generate a £1.25million-a-year crop.

Police at the entrance to the Wiltshire quarry where the drug factory was discovered

Police said of the quarry find: “We are not sure how big the factory is because there are ­significant safety issues.”

Insp Nick Mawson added: “Locals are likely to see police presence as officers gather evidence.

“This work is anticipated to carry on into next week due to the size of the location.”

Bethel Quarry was owned by the Bath and Portland Stone Company.

It stored equipment in World War Two and later became a mushroom farm, closing in 2010.