Four men responsible for the large-scale distribution of drugs across the UK have been jailed.

Paul McIntyre, who is currently serving sentences in prison for drugs-related offences, David Hughes, Scott Gardner and Isaac MacKinnon all previously pled guilty to being concerned in the supply of the Class A drugs heroin and cocaine.

Following a joint intelligence gathering operation by Lothian and Borders Police, Dumfries and Galloway Constabulary and the Scottish Prison Service, it was established McIntyre was continuing to influence activities from his prison cell.

As a result of this operation, several drugs couriers were arrested and addresses in Liverpool and Edinburgh, which were identified as safe houses for the production of heroin and cocaine, were searched and significant amounts of drugs seized.

Police raids on these properties recovered almost 11 kilos of Class A drugs worth almost £850,000.

Around 30 kilos of mixing agents including benzocaine, paracetemol and caffeine were also seized along with over £30,000 in cash and a Rolex watch valued at around £10,000.

At the High Court in Livingston today, McIntyre (28) was sentenced to nine years and six months in prison; Hughes (48) received an eight-year sentence; Gardner (29) was given five years while 34-year-old MacKinnon was sentenced to five years eight months.

So far, 26 people have been arrested various drugs offences as part of Operation Laurel.

Following today’s sentencing a total of twelve people are now serving prison terms of over 52 years.

Detective Superintendent David Gordon said: “Paul McIntyre was already known to police for his involvement in the UK-wide drugs trade and was consequently serving custodial services for his crimes.

“He continued to involve himself in drug crime from prison and when police and prison staff became aware of this a major operation was launched, which was lead by the Lothian and Borders Police Serious Organised Crime Unit. The intelligence received as a result of this operation led to the discovery of various properties across the UK, which were concerned in the supply of large quantities of Class A drugs – all of which have now been seized along with considerable sums of cash.

“This operation is an excellent example of the partnership approach taken by police and the prison service to detect and prevent criminal activity.Drugs have a significant and detrimental impact upon our communities as we are committed to working alongside our partner agencies to identify those responsible and bring them to justice.”

A Scottish Prison Service spokeswoman said: “The presence of drugs and other contraband in our prisons is a serious problem. It is therefore gratifying that joint partnership working of this kind has achieved such positive results.

“We are confident that our ongoing work with Lothian and Borders Police will yield further successes like this in the future.”