Police investigating a potentially hazardous batch of class A drugs circulating in Hertfordshire have issued an urgent safety warning to users in the county.

Officers are urging the community to be aware that nationally individuals are believed to be supplying synthetic opioids under the guise of heroin, which are often far more potent and could lead to overdose, cardiac arrest or death.

Herts police say they are aware of several people who have suffered medical episodes after taking suspected synthetic opioids in the county, and they are working hard to minimise the availability of these substances.

Detective Chief Inspector Mark Clawson, who leads on serious and organised crime for Hertfordshire, said: "While we would never condone the use of illegal substances, we are realistic and understand that people do suffer with addictions, so it is our duty to warn them that there could be a dangerous substance in the drugs they are taking.

"Keeping people in Hertfordshire safe from harm is paramount to our role as the police. This means issuing this warning so people are able to make an informed choice and exercise caution.

"It’s important to note that we are seeing this issue across the country, and it’s not something that’s isolated to Hertfordshire."

DCI Clawson added: "We’re pleased to report that we have already recovered some of these dangerous substances and made three arrests as part of our investigation, which remains ongoing.

"In addition, we are liaising with our colleagues in all 10 of the county’s community safety partnerships, who support those with drug addiction, so they’re able to share our messaging directly to their service users."