THE death of a 44-year-old man is being investigated by police as part of a probe into the illegal sale of insulin.

Detectives are examining the case of Clayton-le-Moors grandfather Shane Raeburn amid fears he had taken the drug.

Two of Mr Raeburn's friends have also fallen ill - one seriously - and police believe they had also taken insulin.

The drug is used to treat diabetes but police said neither Mr Raeburn or his two friends had the condition.

Officers said they were probing two possibilities about why a non-diabetic would take it - either to get high or to build muscle.

They have arrested and released three people on bail - a 40-year-old woman and a man, 30, both from Clayton-le-Moors, and a 19-year-old man from Accrington - pending further inquiries.

Police began probing the death of Mr Raeburn, who lived in Barnes Street, after a post-mortem examination proved inconclusive and two of his friends were taken ill after taking the drug.

Further tests are being carried out on Mr Raeburn in a bid to establish why he died.

Det Chief Insp Paul Withers said police were due to interview associates of the three friends in a bid to find out more after the case was referred to them by Blackburn coroner Michael Singleton.

He said: "Although a post-mortem examination has taken place, the cause of death is still unascertained at this time.

"Police are also investigating the circulation of ampoules of insulin in Clayton-le-Moors.

"Three people have been arrested in connection with the circulation of the insulin and have been released on police bail pending further inquiries."

One man is seriously ill in the Royal Blackburn Hospital. The other needed treatment but has since recovered.

Mr Raeburn died in the early hours of last Wednesday, but detectives were only handed the file by the coroner on Tuesday.

Police issued a warning about insulin at the weekend after revealing that Mr Raeburn's friend was seriously ill.

Officers said they were unsure of the origin of the insulin but that they were investigating how it had come to be on sale illegally.

Insulin is usually given to diabetics to control their blood sugar levels.

But internet sites detail how bodybuilders have started using insulin because they feel it can provide further muscle gains. This is said to work by helping to regulate glucose levels and bring nutrients to muscles.

However this is very risky. Police say that 10ml ampoules of insulin - what they suspect is on sale illegally in Hyndburn - can cause non-diabetics to lapse into unconsciousness, a coma and can even prove fatal.

Police said the small glass ampoules contain a milky white liquid, possibly sealed with an orange cap and should be handed in to police if discovered.

People with any information about the drugs are being asked to call Blackburn police on 01254 51212 or Crimestoppers, in confidence, on 0800 555 111.

Brett Ainsworth, also of Barnes Street, said he had known Mr Raeburn, a father of eight for 25 years.

Mr Ainsworth, 47, said: "There's all kinds of rumours flying around so we don't know what happened.

"I will miss him a lot and it has. We often went drinking together."