A chemical used to de-worm farm animals has found its way into some batches of UK cocaine, according to a recent report.
Some drug users say that the laced cocaine has caused their skin to discolour and rot.
There is a four in five chance that the UK's cocaine supply has been blended with levamisole, a chemical that causes human flesh to decay, a report found.
The chemical induces blood cells to rupture, especially in the ears, nose and fingers, causing skin abrasions, discolouration and rotting.
Doctors said that levamisole, often used on pigs, cows and horses, lowers the white blood cell count, which makes the drug user ‘feel like they have HIV’.
Drug fatalities have increased drastically across the UK as the purity of heroin and cocaine has risen, according to figures released last year.
It seems the risk to users is even higher now it's emerged gangs are routinely using the powerful deworming agent to cut the class A drugs, The Mirror reported.
Police have issued the warning amid reports of a series of deaths and overdoses in a quiet seaside town, where super-strength heroin and cocaine is being sold.
Detectives in Eastbourne said the incidents have occurred since April and in at least two cases the cocaine was found to be nearly 100 per cent pure.
Detective Inspector Neil Ralph said: "We investigate all drug overdoses and drug-related deaths and look to identify who has supplied the drugs and seek a prosecution.
"This can be difficult at times because it is often the case that the only person who knows the source of the drug is deceased."
A study in the British Medical Journal said doctors were trying to treat a woman with mysterious open skin lesions and severe abdominal and joint pain but were stumped as to the cause of her symptoms.
After running chemical tests on her hair, the team realised that the condition was caused by levamisole-tainted cocaine she had taken.
Levamisole poisoning can cause skin lesions and discolouration and rotting of the skin when blood cells rupture, particularly in extremities such as the ears, nose and fingers.
Ingesting the chemical can also lead to a drop in white blood cell count, which leaves sufferers vulnerable to other conditions.
"It's a little bit like having HIV," Dr Noah Craft, a dermatologist at the Harbor-UCLA Medical Center, said during a 2011 spate of levamisole poisoning cases in the US.
About 10 per cent of those patients will die from severe infections, and they may be walking around like a ticking time bomb.
The authors of the study said in part they wrote the report to highlight how difficult it can be to diagnose people who do not admit to drug use.
"It is essential for patients to be honest with their health care providers, so they can deliver the right care," lead researcher Dr Tjeerd van der Veer said.