A SUN On Sunday investigation has uncovered how deadly diet pills are being sold online and covertly shipped to British slimmers.

We bought five toxic “slimming aids” online without any problems, just days after a coroner warned of the potentially fatal effects the drugs have.

Our investigation comes at a time when experts say users are more likely to turn to unlicensed substances such as Dinitrophenol (DNP) in a last-ditch bid to lose weight over the festive and New Year party season.

DNP — which was once used to make EXPLOSIVES — is easy to get hold of and led to the death of 25-year-old Rachael Cook, from Worthing, West Sussex, in May.

Her inquest was told she may as well have been “taking rat poison”.

DNP is not a controlled substance despite being linked to several deaths in the UK and subject of an Interpol notice issued to 190 countries.

But our investigators were able to buy a large batch of the unlicensed synthetic chemical within minutes.

Overseas traders promised to cover up the contents of the killer packages — to stop customs officials seizing the yellow powder and to stop worried parents knowing the truth.

Coroner Penny Schofield told last Friday’s inquest: “I urge those currently taking the drug or considering doing so to think again.”

Yet it is a warning revellers are unlikely to take notice of as they try to shed pounds to slip into a festive party dress or outfit.

Tam Fry, from the National Obesity Forum, explained: “People are taking drugs that put their lives at risk in order to look their best at a party.

“These pills are frightening and can cause serious health complaints and even death.

“You can go very, very wrong with slimming pills.”

‘I’ll never forget the drug sweating out of her’

DNP works by speeding up the metabolic rate so the body burns more fat. But it causes the body to overheat and BURNS the insides of users. It has officially led to the deaths of 16 people in Britain alone.