By Duncan Crawford
The so-called 'cocaine torch' uses ultra-violet rays to check clubbers
A special drug torch used by police to catch people who snort cocaine is now being used by door staff at pubs and clubs in Blackburn.
The so-called 'cocaine torch' uses ultra-violet rays. Police in Lancashire say it lights up bright green if traces of the drug are found on people's faces.
Pc Andy Duxbury, licensing officer in Blackburn, told Newsbeat how it works: "The nasal hairs on the inside of the nose and around the nose area illuminates bright green," he said.
"You can see if they've taken cocaine. That gives us the power to search them and see if they've got any further substances on them."
There are concerns about the legality of the torch though. The drug charity Release say it might be illegal as it could be a breach of privacy.
Privately, officers from another police force have also told Newsbeat they are worried about the human rights implications and said they had doubts about the torches effectiveness.
Officers in Blackburn have been testing out the torch for the last two months.
They say it acts as a deterrent and hope it will lead to a reduction in violence and people using cocaine.
"It's a great preventative tool," added Pc Andy Duxbury. "If people know that they've got these torches and they're going to be using these torches, it's going to put people off coming into town, who've taken cocaine.
"And that will probably mean less trouble for us, less anti-social behaviour."
Officers in Blackburn say the torch acts as a drugs deterrent
Blackburn's Bar U scheme, run by all licensees in the town centre, bought 20 of the torches after police deemed them a success.
Doorman John told Newsbeat he's tested around 100 people and caught four or five: "They're not best pleased. I say no entry, that's it."
Police say cocaine is cheaper to buy now because it's mixed with so many other substances.
Helen Griffiths is relief manager at FJ Nichols. He said: "A lot of people use cocaine and drink at the same time. That as a combination just makes people really violent."
A group of girls on a night out were unhappy about being searched. One told Newsbeat: "I think it's absolutely ridiculous. I'm not a cocaine addict. We've just had a cocaine torch shoved up our noses for no reason."
But Pc Andy Duxbury says the majority of people aren't bothered: "I understand that some people are against it.
"But if they've got an issue with it, then they don't have to be searched. They can decide to go somewhere else. It's a condition of entry."