Alston Road on Hellesdon Park Industrial Estate, Hellesdon, where a cannabis factory was discovered

Workers at a Hellesdon industrial park have spoken of their shock after a cannabis factory was discovered by police behind a false wall following a raid at a business on the site.

Alston Road on Hellesdon Park Industrial Estate, Hellesdon, where a cannabis factory was discovered.

Officers from Sprowston seized 60 plants with an estimated street value of £30,000 after they smashed their way into a unit on Alston Road at Hellesdon Park Industrial Estate on Wednesday night.

People working at businesses on the Hellesdon estate have told they were shocked and surprised to discover they had a cannabis factory in their midst.

Roy Rutland, 58, an engineer at Mobility Supermarket Norwich, which neighbours the raided unit, said: “I’m just surprised by how near the thing was – it’s next door to you. You get odd smells on industrial estates, but I wouldn’t have associated it with drugs.”

The day after the raid about eight or nine police vehicles, including Crime Scene Investigation, remained on scene to gather evidence from the address.

Mr Rutland, who was able to see inside the unit, said: “The first two thirds was set up like a wood yard, but they had a bit sectioned off. We couldn’t see anything. It was a false wall.

“It was amazing what they took out of there. They were carrying out bags and bags and asked for a carving knife to cut down some of the plants.”

A 50-year-old man who works on the estate, but who did not want to be named, said: “You hear about these things, but you don’t realise how close you are.

“It was a shock to discover what it was.”

Police said the warrant was carried out as a result of “local intelligence” and urged people to continue to report anything suspicious.

Supt Carl Edwards said: “Illegal drug activity can often be linked to other criminal offences such as burglary and theft, therefore having a detrimental impact on society.

“These drugs often lead to physical and mental health problems for those who use them and bring misery to the individuals and their families.

“For these reasons we would encourage people with information concerning drug activity to come forward, either by contacting their local policing team directly, or anonymously, through Crimestoppers.”

Call police on 101, or Crimestoppers, anonymously, on 0800 555 111.

A 38-year-old man was later arrested at an address in the city following the raid at Alston Road. Enquiries led officers to search an industrial unit at the Bowthorpe Employment Area the following day where around 20 cannabis plants were seized. A 32-year-old man was arrested and both men have been released on conditional bail until April.