Police officers examined mobile phones recovered from drug couriers and found numbers linking the handsets to several belonging illegally to Christopher Smith.

Analysis of the dialogue from these phones proved that he was directing the owners to traffic cocaine and heroin on his behalf from behind bars at HMP Edinburgh.

Smith, 34, of Elgin, was sentenced at the High Court in Livingston after pleading guilty to directing and organising the supply of controlled drugs.

He was also made subject of a serious crime prevention order, which will last for three years and is designed to prevent him returning to crime when he is released from jail.

Moira Orr, who leads on major crime at the Crown Office, said: “Christopher Smith was intent on profiting from criminality even from his prison cell by flooding communities with drugs and carrying out deals as part of an organised crime network.

“This was an illegal enterprise, run from his prison cell, and it is clear his role was pivotal.

“As prosecutors, will always take action against those attempting to break prison rules.

“The imposition of a serious crime prevention order also sends a message to drug dealers that we will not stop at prosecution and will work to restrict their ability, even after they have been released from jail, to return to criminal activity.”