What could be one of the biggest drugs factories ever found in the region has been discovered in Calne.

A staggering amount of cannabis was being secretly nurtured at the Porte Marsh Industrial Estate, in a building cunningly disguised as a Drakes Ceramics warehouse.

And after that find in the early hours of yesterday morning, drugs squad detectives swooped on another unit in Harris Road and are believed to have found another growing factory of a similar size.

A member of the public alerted them to the other hoard of drugs and a man in his 40s was arrested inside the second plant, which was raided at around 7.30pm last night.

Sgt Phil Connor, of Calne Police, said: "Whilst officers were working at the scene they were approached by a member of the public who said he thought he had smelt cannabis from another unit on the same road.

"Officers were deployed to get a warrant in order to search the premises when a man in his 40s came out of the unit and surrendered himself to officers.

"He confessed he had been hiding in the unit for some time."

Throughout yesterday, forensic teams laboriously took apart the first factory and were forced to call in reinforcements to handle the amount of cannabis, the value of which has yet to be totted up.

A flat bed lorry outside the ceramics businesses was seized and police have not ruled out making further arrests.

Charlotte Newman, a worker at K & R Chem-Dry, a carpet and upholstery cleaners opposite the scene, had no idea what had really been going on over the road.

She said: "it is a real shock, you wouldn't have thought something like this was going on down here.

"I had wondered what was going on there, because I've never really seen anything happen.

"I look at the place all day and never saw anyone come or go and certainly never saw any ceramics.

"To think they had got away with this all that time."

Police wo stormed the scene said cannabis was growing "from wall to wall and floor to ceiling", with a street value that could climb into the tens of thousands.