Sussex Police have issued a warning that "100% pure" cocaine is on sale in the UK.
Officers claim the super-strength version of the drug, along with heroin, was linked to two deaths in Eastbourne.
Police have seized samples of the drug and advised taking any form of it is dangerous, especially when the purity of the substance is unknown.
In 2016, the Global Drug Survey found a rising purity of cocaine on the streets of the UK.
Across the country in 2015, the Office of National Statistics (ONS) says there were a total of 3,674 deaths from drug poisoning.
ONS figures show deaths from cocaine alone have risen from 112 to 320 in just five years.