University students looking for a 'giggle' by using drugs like cannabis are fuelling the misery of modern slavery, it has been claimed.

Devon's police commissioner wants the county's students to think again before using so-called recreational drugs.

Speaking as police revealed details of raids on huge cannabis factories, including one in a disused Torquay nightclub, commissioner Alison Hernandez said: "Talking about recreational drugs makes it sound like it's fun, and you can do it, and it's legal, but it's not.

"There's an awful lot of suffering going into you having that giggle."

She also urged the public to be on the lookout for the telltale signs of drug 'factories' across the county. She said it was remarkable that nobody had spotted the activity around the former Bohemia nightclub in Torquay's Torwood Street, where one of the raids took place.

Hundreds of plants and drugs with a street value of up to £350,000 were seized from a sophisticated 'factory' inside the old nightclub, and CCTV cameras spotted a suspect hiding on the roof of the building.

A total of five men have been arrested following the police 'Operation Scorpion' across the south of England. Officers executed nine warrants and seized more than 850 plants with an estimated street value of more than £470,000.

Detective Superintendent Alex Doughty, who led the operation, said: "The operation is a regional project focusing on drugs with the aim to make the area a hostile environment for drugs supply.

"Our officers have been targeting organised criminals who are growing cannabis and using this to harm our communities – something that we are committed to tackling."

Ms Hernandez, who is the police and crime commissioner for Devon and Cornwall, said many of the people involved in the production of cannabis may have been the victims of modern slavery, working under severe threats and pressure.

"There are links with modern slavery in relation to most drug dealing," she said. And she urged the public to be vigilant and look for tell-tale signs of drugs factories.

These could include people working to divert electricity supplies, bulk-buying food and drink for 'slave' workers and buying large quantities of plant pots and growing equipment.

And, she said, casual drugs users had a part to play in ending the misery of modern slavery.

"They think it's a bit of a laugh, but it isn't," she said. "People need to make more of an ethical decision about what they are doing in their lives.

"I am also making a plea to university students. Drugs use is still rife in young people's lives.

"They think it's fun. They think it's a time to take risks. They think they are going to have a laugh.

"But they need to start making these ethical decisions they think they are making about the environment about people as well."

As a result of the raids, a 51-year-old man from Camborne has been bailed until September; two men aged 28, 24, both from South Wales, and a 37-year-old man from Plymouth, have been released under investigation pending further inquiries.

Idajet Beqiri, aged 24 and of no fixed abode, was charged and pleaded guilty to being concerned in the production of cannabis, and will be sentenced on 27 July at Exeter Crown Court.

Det Supt Doughty said the Torquay nightclub raid involved around 30 police personnel including a dog unit.

"Using the element of surprise, officers forced entry into the building," he said.

"Thanks to the use of Torbay Council CCTV, the offender was located hiding on the roof. He was arrested and taken into police custody and subsequently charged."

Officers found 416 cannabis plants with a potential yield of up to 35kg.

Det Supt Doughty went on: "All five south west police forces have joined together to send a clear message to organised criminals and those who cause harm in our communities, that there is no place for them in our region.

"We will continue to execute these warrants, target these organised gangs, and protect our communities."