A young man has died after the suspected consumption of a weight loss drug bought online, the first case of its kind in Ireland, according to health authorities.

Two investigations are under way into events surrounding the death of the man, in his early 20s, who took a product containing the drug, Dinitrophenol (DNP).

The investigations are being carried out by the Health Products Regulatory Authority and gardaí.

DNP is illegal and was linked to the death of a young woman in the UK in April and cases elsewhere where there were serious side-effects.

The drug accelerates the body's metabolism but can do so to a dangerously fast level.

The HPRA said the death occurred in mid-May but it was only recently notified about the case by a healthcare professional and is now issuing this public health alert today.

The case has also been referred to the local coroner.

HPRA's chief executive Pat O' Mahony urged members of the public never to use the internet to source slimming products, or any prescription medicines at any time.

No product has been located in relation to this case.

DNP is usually sold in yellow powder or capsule form, but also as a cream.

The risks are magnified by illegal manufacturing conditions.

The family of the dead man are assisting gardaí and the HPRA and an analysis of computer hardware is part of that process.

DNP was the subject of an Interpol global alert in May and it is not approved for use anywhere in the world.

The HPRA detained 93 capsules containing DNP this year.

It is sometimes used for dieting and body building.

DNP was first used to make explosives in the First World War.

Workers exposed to it lost weight, as well as suffering other ill effects.

It was used in the 1930s to boost metabolism but was taken out of circulation because of several deaths.