Benzylpiperozine – known as BZP – is said to have similar effects to Ecstasy and amphetamines.

Largely unheard of, the psychoactive stimulant – originally designed as a cattle wormer – is marketed in the UK as a "legal high", although concerns over its safety have resulted in it being banned in Australia and the US.

Two people have died after mixing BZP, which is also known as Legal E, Nemesis or Euphoria, with Ecstasy and it has been found during post mortems on two road accident victims in Britain.

There have been three police seizures of the tablets in Lancashire since January, including one man found in possession of around 100 BZP pills in Blackpool.

Powder

Although not illegal to possess in the UK, it is illegal to produce the drug without a licence.

Det Sgt Paul Boyes, of Blackpool Police's intelligence unit, said: "We've had two or three seizures this year in Lancashire and have arrested people and confiscated drugs suspected of being Ecstasy tablets.

"Once they have been tested it would appear there is no offence in possessing this substance.

"Obviously if it has the same effect as Ecstasy or amphetamine it's disturbing.

"If someone attempts to sell you this in a nightclub you should bring it to the attention of the management and the police."

BZP is usually available as a powder, which may be packaged in capsules or small plastic bags.

It can also be pressed into tablets, many of which are embossed with logos. They sell online for around £10 for two pills.

Medical experts warn the drug could cause death in rare circumstances.

Dr Mike Mawhinney, of the Northern Ireland Department of Health which launched a study of the drug, said: "Ingestion of BZP can result in agitation, vomiting, abdominal pain, seizures, abnormal heart rhythms, colic, diarrhoea, allergic reactions and fever.

"In rare cases, users may also suffer from serotonin syndrome, which can result in death."

In March the Government's advisory committee on the misuse of drugs began the process of making BZP a controlled substance.

It is likely to become a Class C drug before the end of the year.

Natural

Public safety officials in Blackpool warned that the practice of finding alternatives to illegal drugs was nothing new.

Paulo Pertica, of BSafe Blackpool, said: "When you are talking man-made drugs there are a number of different recipes and when one becomes illegal there will already be someone working on coming up with the next thing.

"People have been doing this for years and there are also many things on the market which are made of natural ingredients.

"The advice to people who have taken it would be the same as if they had taken Ecstasy."

The drug is considered so dangerous by US authorities that it is classified as schedule one, the same category as heroin.

Magistrates in Blackpool have issued a warrant for the arrest of James Jones to face charges of producing BZP without a licence.

Jones, of Park Road, Blackpool, faces four offences brought under the 1968 Medicines Act.