America's East Coast is battling a new and frighteningly powerful drugs curse.

It is casting a dark and menacing shadow over grim inner cities, sweeping into wide stretches of middle-class suburbia, and is now threatening tranquil rural areas.

The drug is a new variation of heroin. The cartels have cut heroin with a surgical drug called Fentanyl, normally used as an anaesthetic or painkiller for cancer sufferers.

It is marketed in the cynical and ruthless world of the drugs barons as a cleaner, purer heroin hit.

But this is the devastating fact about Fentanyl: It is 80 times more powerful than morphine and hundreds of times more potent than heroin.

So as the first batches hit the East Coast - from Vermont through Boston, New York and down to Baltimore - deaths have spiked.

In the last few months, the heroin-Fentanyl combination killed 37 people in Maryland alone.

It feeds on a growing heroin addiction problem across America. The numbers of addicts and overdoses have nearly doubled over the last five years.

On the streets of Baltimore we met with Michael Gimbel. He's a former heroin addict who not only survived but became this city's drug czar. Gimbel has seen the crisis from both sides.

He warns that America's drug users have no chance of surviving this new batch of heroin. It kills quickly. It's impossible to judge the "right" quantity.

All demographics are at risk - white, and African-American, young and middle-aged, women and men, previous users and a new generation.

Prescription drugs are getting more more expensive on the street. Heroin is becoming cheaper. So desperate addicts are beginning to switch. Gimbel says that Hoffman's tragic death is an urgent wake-up call for America.

A spokesman for Britain's National Crime Agency said: "The National Crime Agency (NCA) is alive to the potential threat posed by fentanyl, which is not currently prevalent in the UK.

"However, the NCA together with partners continues to carefully monitor both its use and links to organised crime."