An early warning system to spot synthetic opioids and other drugs is being developed by ministers, in an attempt to prevent a US-style fentanyl crisis.

It will test waste water and spikes of overdoses being reported by the emergency services to track the presence and strength of synthetic drugs across the UK in real time. 

Chris Philp, the crime and policing minister, will announce details in his speech at the annual conference of the UN Commission on Narcotic Drugs, in Vienna on Friday.

In The Times, Mr Philp said the early warning system will help Britain to avoid a crisis on the scale of the one the US is experiencing. He said the “public need to be aware of the risks”. 

There is also a lack of awareness about the fact that synthetic opioids are significantly more toxic than better-known drugs such as heroin, he added.

He said: “Sadly, some seek these drugs out. Just as tragically, many don’t — and are unknowingly taking illicit drugs cut with a potent synthetic opioid. Misusing drugs is playing Russian roulette with your life.”

Fentanyl is a form of synthetic opioid which is up to 50 times more potent than heroin and 100 times stronger than morphine.