Krokodil, the flesh-eating drug that turns skin to scales and kills users within three years, is emerging in the UK, an expert has said.
The drug and its effects were recently highlighted after two cases were reported in the US state of Arizona, raising fears its use is becoming more widespread.
Speaking to Vice, Allan Harris, a Gloucester-based specialist in treating drug addicts and the homeless, said there are warning signs krokodil is now infiltrating the UK.
Krokodil use became popular in Russia about 10 years ago. It is an inexpensive drug similar to heroin, only the effects last for a shorter period of time.
It is much cheaper than heroin and can be made from household items, including codeine, lighter fluid, gasoline and paint thinner.
Writing for the Independent, Harris said: "The drug causes death of muscle and soft tissues at the site of injection and can lead to marked shortening of life expectancy in users of the drug - some argue once people become full-time krokodil addicts, they have a life expectancy of less than a year.
"Its name [the Russian for Crocodile] is thought to have come from the green scaly colour the affected body tissue becomes, before it is lost completely from the effects of gangrene."
Harris said he has only seen one case of krokodil use in the UK - a homeless man who was a long-term heroin user. He died earlier this year and tests are currently being carried out to establish whether Krokodil was the cause.
Speaking about the UK's first reported victim, he told Vice: "At the time, I just thought it was the citric acid burns of a heroin user, but looking back the tissue destruction was far, far in excess [of what you'd expect from that].
"When you get citric acid issues you usually get second-degree burns, but this actually took out a huge crater of all the forearm muscle. When you took out the dead tissue you could actually see the tendons moving at the base of this crater and the bones as well - so pretty much like these horrific pictures you see on the warning leaflets for krokodil.
"It actually got to a point where he couldn't move his right hand anymore because it weakened the muscle so much. He could roll a cigarette and that was about it."
Speaking about why krokodil is becoming more popular, Harris said a shortage of heroin is leading drug dealers to turn to cheaper options: "There has been [a shortage of heroin] recently. We saw it historically; obviously we had the war efforts in Afghanistan, where they destroyed huge poppy fields.
"Throughout the year there was a dip in availability, so users were taking heroin that was cut with so much stuff they were getting detox symptoms, because it wasn't strong enough.
"More recently there has been a decline in heroin - I think through better policing - though the availability of it seems to be on the up again now. Drug dealers are getting to supplies again and it will probably takes the onus off people making their own heroin substitutes, such as krokodil."
Harris said there is not enough public information and warnings about Krokodil and its effects.
"The news of it getting out has been quite slow, really; I think there's not been much publicity about it and I hope it doesn't come out, but it's so easily made I think it's only a matter of time before people do start trying to make their own stuff.
"I think as far as krokodil use goes, it is incredibly bad news but I think you should avoid it at all costs."