Police are investigating the circumstances surrounding the death of a 26-year-old man who died in a property in Pembroke Dock last Thursday.

HM Coroner has been informed. Next of kin have been informed.

Toxicology tests have been requested.

A second man is in hospital receiving treatment.

Police are aware that the men had been taking drugs, believed to be mephedrone and commonly known as meow meow, prior to his death.

"There are some serious side effects to using meow meow," said DI Anthony Griffiths  

"These can include heart attack, seizures, sweating and paranoia. This drug is a fine white or of-white crystalised powder which was originally sold as a legal alternative to cocaine and amphetamine. However, since April 2010 it became illegal to possess or supply the drug.

"There are many effects of mephedrone that include users feeling anxious and paranoid. The long-term side effects are still largely unknown, but the drug is very addictive."

He continued: "Some signs to look out for after use, known as the 'come down', are that users can become very emotional and some can be quite aggressive. The drug also suppresses the appetite and need for sleep and users can quickly suffer from sleep deprivation and lack of nourishment.

"Users will also develop a unique odour, similar to stale cat urine. They will be unable to smell it on themselves, but through perspiration it will be smelt on skin, clothes and hair.

"But apart from the health dangers, being caught in possession of meow meow could mean up to a five year jail sentence.

"A conviction for a drugs offence can also prevent you travelling to foreign countries and restrict the kind of jobs you can apply for."