Thinking back, John Melbourne estimates that he summoned police to the family home almost 30 times in a single year because of his son.

While Will’s drug use was linked to mental health issues and ‘wasn’t a recreational thing’, his unpredictable behaviour had left his loved ones afraid for their safety.

In December, after moving into assisted accommodation, the 19-year-old placed an online order for oxycodone - a highly addictive painkiller that is also effective at relieving anxiety. But the 20-tablet pack that dropped through his letterbox actually contained a type of extra-strength opioid - nitazenes - and after taking just two of the pills, he died almost immediately.

Nitazenes were unheard of in Britain at the time of Will’s death five years ago. It was another four months before the drug was even first identified here - from a sample of white powder found in the back of a taxi in Wakefield, West Yorkshire.

Traces have since been detected in street heroin, cocaine and cannabis, as well as black market pills being sold as diazepam (Valium) and other sedatives.

Just this week, the Metropolitan Police revealed that an investigation is under way into the ‘sudden deaths’ of a 28-year-old man and a 20-year-old woman in Southall, West London on May 26. The pair allegedly passed away after taking an oxycodone pill which drug-checking charity The Loop warned also contained nitazenes.

According to one user, taking nitazenes feels ‘like a little bomb going off in your brain’. The description goes some way towards explaining quite how powerful they are - and why this new street drug threatens to take many more British victims in coming years.

According to one user, taking nitazenes feels ‘like a little bomb going off in your brain’

In many instances, the drug is making its way here from underground Chinese labs churning out fake anti-stress medication. But it is also being secretly added to batches of drugs like heroin to boost their strength and make up for supply shortages.

Regardless of what form it takes, Home Office figures now show that at least 400 nitazene-related deaths have been recorded across the UK since June 2023. Yet as we shall see, new research suggests this could well be a severe underestimate as nitazene-laced drugs flood the market.

For his part, Will - who had been diagnosed with autism as a boy - was already smoking large quantities of cannabis when he dropped out of school during sixth form. He later moved on to harder substances such as the horse tranquilliser ketamine.

At that stage, he was still living at home in Wilmslow, Cheshire, with parents John and Sally - both professional classical musicians - and younger sister Alice, now 19 and a student at Glasgow University.

John, 55, a percussionist with the Manchester Camerata and the Northern Chamber Orchestra, admits that ‘we were sort of worried about her [Alice’s] safety as well as our own, to be honest’.

He says of Will: ‘There were numerous times that we went to A&E with him because he had either taken too much or had deliberately taken an overdose.

‘He was never exactly suicidal, but he was very, very depressed. He always said that he wouldn’t take his own life because of us and that he wouldn’t put us through it, but he wasn’t happy and sometimes he didn’t want to carry on living.

‘Eventually, it got to the point where we couldn’t allow him to stay in the house any longer. We also used to have the police out regularly as well . . . I think we called the police something like 28 times in a year when he was getting difficult and violent and we just didn’t know what to do.’

By July 2020, as the nation emerged from the first pandemic lockdown, Will had his own flat in assisted accommodation where the tenancy rules stipulated that he kept away from drugs. His father believes he abstained ‘for quite a long time’, but computer records later showed he ordered oxycodone over the dark web about a week before he died.

It later emerged in a coroner’s report that the tablets were laced with metonitazene, a compound 50 times stronger than heroin and roughly the same strength as fentanyl - the opioid that has ravaged American cities such as San Francisco, where open-air drug abuse is rampant and addicts congregate on street corners littered with drugs paraphernalia.

Last year, metonitazene was among 14 varieties of nitazenes banned by the Government as class A drugs on the grounds that they are ‘highly addictive and incredibly dangerous and pose a higher risk of accidental overdose’. Other nitazenes can be up to 500 times stronger than heroin, according to The Lancet.

Last year, the medical journal warned that the number of reported deaths in the UK where nitazenes has been detected in post-mortem toxicology ‘is likely the tip of the iceberg, as many tests are still in process and emerging drugs are not routinely tested for’.

Doctors issue warning over Chinese-made opioid nitazene that is deadlier than fentanyl and 1,000 times more potent than morphine

Oxycodone has a high abuse potential and is prescribed for moderate to high pain relief

Of the tablets that claimed Will’s life, his father John says: ‘He only took two and, from all the evidence we’ve seen and what was displayed at the inquest, it appears that he died very quickly after.

‘He was ready to go out, he was meeting some friends, he had his coat on, his shoes - and he obviously just decided to take these two tablets before he went.

‘And he was found on the floor and his [Covid] mask was still on, which kind of implies that it was so quick that he must have lost consciousness very quickly.’

John stresses that his son saw his drug use ‘as a way of medicating himself . .. of coping with his own anxiety and fears and problems’. But even though Will had read up on pharmaceutical drugs, John concedes that he ‘probably didn’t know about nitazenes’.

Britain often considers opioids an American problem. But the truth is we have an opioids crisis of our own.

In the US, the situation is so severe that individual states publish overdose figures on a publicly available database. But no such ‘dashboard’ exists here in the UK - although one is said to be under development - and the Government appears reluctant to publish detailed data at all.

International records show, however, that as of early last year, nitrazanes were most frequently identified in the US, Canada, Latvia, Estonia and the UK - in that order.

The findings coincide with a sharp increase in drug-related fatalities. Figures show that there were 5,448 deaths by drug poisoning in England and Wales in 2023, an 11 per cent increase on the previous year and the highest number since records began in 1993.

Cocaine deaths rose by 30 per cent from 857 to 1,118 - nearly ten times higher than the total for 2011. Many believe much of the increase is down to drugs being contaminated with nitazene and the consequences are being felt everywhere.

No specific geographical breakdown is available for nitazene deaths. But by sending Freedom of Information requests to each of the UK’s ambulance services, Dispatch, a new online magazine, was able to establish how many times naloxone - a nasal spray used to reverse opioid overdoses - had been administered in 2023 and 2024.

Several areas registered sharp increases in the space of a year. Incidents in Bournemouth, Christchurch and Poole, all in Dorset, went up from 170 to 290, for instance, while Leicester rose by 217 to 507. Birmingham recorded the highest overall number at 720 last year, up by 82 on the total for 2023.

But these figures are unlikely to be the full picture either. They do not include instances where naloxone — an emergency antidote for opioid delivered via an injection or nasal spray — has been administered in hospitals, or on the street by police or support workers.

And of course, they do not show where naloxone hasn’t been used, or where opioid-overdose deaths have taken place.

The history of nitazenes begins in the 1950s in the Swiss city of Basel. At the time, chemists at the Ciba Pharmaceuticals laboratory were trying to develop a new painkiller because of depleted morphine stocks after the Second World War.

But the fruits of their research - nitazenes - were never cleared for public use after they were found to cause fatal breathing problems during trials.

Even if it hadn’t been for that issue, it seems likely that regulators would have refused to approve them anyway because of their extraordinary potency and the potential for addiction.

For decades, nitazenes remained largely forgotten. But that all changed in 2019 when Donald Trump, then halfway through his first term in the White House, persuaded the Beijing government to ban the manufacture of fentanyl - which some labs had been exporting from China to the US.

Some labs responded by selling the raw materials for fentanyl to Mexican drug cartels, who then synthesised the drug themselves and smuggled it into America. But others effectively rediscovered nitazenes, disguised them as anxiety-reducing pills such as oxycodone and started selling them on the dark web to unsuspecting buyers.

Three years later in Afghanistan (which at the time was responsible for producing more than 95 per cent of Europe’s heroin), the newly-installed Taliban regime announced an all-out ban on the cultivation of opium poppies. Given that the flowers provide the key ingredient in heroin, unscrupulous dealers eked out dwindling supplies by mixing the drug with nitazenes.

The upshot was this double wave of opioids of unprecedented strength being unleashed on the rest of the world.

Against that stark backdrop, it is hardly surprising that the latest assessment from the National Crime Agency - Britain’s FBI - on serious and organised crime warns that ‘taking drugs has never been more dangerous’. It points to a ‘significant escalation in the criminal use of nitazenes as a cheap way to increase the strength of certain drugs, particularly heroin’.

Yet, as in the case of Will, there are mounting fears about the dangers facing people who are simply trying to quell their anxiety and related conditions.

Described on an internet tribute page as a ‘most beautiful soul’ who ‘touched so many people in his short life’, Alex Harpum died in 2023 after taking what turned out to be fake anti-anxiety pills. The 23-year-old had just finished a music degree and hoped to become an opera singer.

His mother Anne Jacques, from North Wales, said last year: ‘He was always trouble sleeping and this had got worse with his ADHD medication.

‘My hunch is he probably bought them to calm himself down and get some sleep.’

‘I think there are a lot of parents out there who assume that their kids would never do anything like this.

‘Maybe’s seeing Alex’s profile - who he was, what he was doing in life - [might] just perhaps make people think twice and think, ”Actually my child could be doing this”.’

For his part, John Melbourne says as he reflecting on the ‘terrifying danger’ posed by nitazenes: ‘I still think that if you asked the average person in the street, I’d be surprised if one in a thousand had heard of them - and that’s worrying.’

He adds: ‘To me, it’s the same as murder.

‘If you’re selling something to somebody that will kill them, then to me there’s no difference to stabbing them or shooting them - it’s the same.

‘It’s not like you go to hospital and you think, “Well, that was a close one.” You just won’t get the chance.’

A version of this article appeared on dispatch-media.com