Wiltshire Police are warning partygoers to avoid taking legal highs this festive season.

During the Christmas period, more people are likely to be offered legal highs or new psychoactive substances (NPS).

Many of the chemicals used in these substances have not been tested and so their effects are not known.

Three substances in particular have been flagged as being in circulation in the Swindon area.

These are: MDVP: This is in the form of white powder and is not actually legal at all. This is a Class B drug. This drug is in the same family as Mephedrone so is a powerful and long acting stimulant drug.

PVP: This is sold locally in crystal form. PVP is a schedule 1 controlled drug in many countries after several deaths being attributed directly to it.

ETIZOLAM: This is quite a well researched drug and an analogue of Benzo’s - so it tries to copy its effect. If you mix this with other drugs including alcohol, the risk of an overdose increases massively and there have been deaths linked to this. In the UK this year alone, 52 people have died after using NPS drugs.

Inspector Paul Saunders said: "Even though these drugs might not be illegal, it is still very difficult to know exactly what is in them and the affect they might have on an individual.

"I would urge everyone to steer clear of illegal drugs of every variety and legal highs as the associated risks simply are not fully known.

"We want people to have a safe and enjoyable Christmas and this is encouraged by limiting the risks that are taken.

“If people are intent on taking legal highs we urge them to not use them alone, not to mix with alcohol and seek medical attention immediately if you begin to feel unwell.

"I would also ask that anyone with information as to where these substances are being sold to contact us straight away."

Information should be directed to Wiltshire Police on 101 or Crimestoppers on 0800 555 111 where information can be left anonymously.

Advice and support is also available from CRI - the drugs and alcohol abuse charity based in Swindon.

They can be contacted on (01793) 611 870 or by visiting their centre at Plaza 1, Sanford Street, Swindon, SN1 1HE.