A gang that distributed nearly £1 million worth Class A drugs across Fife, Tayside, Edinburgh and Ayrshire was convicted at the High Court in Glasgow on Thursday.
The drug empire was run by Stephen Nisbet from his cell in HMP Edinburgh with assistance fro his brother James.
Nisbet, who is also serving a life sentence for murder, will be sentenced at a later date.
Other members of the gang convicted at the High Court were John McMahon, Rachel Gordon, David Milne, Robert Morland, Ronald Harrison and Allan Harrison.
Nisbet has since been removed from HMP Edinburgh and is now housed in a different part of the prison estate.
This conviction is the result a Police Scotland covert operation, Operation Lapstone, which has been led by the forces Organised Crime and Counter Terrorism Unit (OOCTU).
The operation ran for seven months and led to the dismantling of a major and established crime group.
OCCTU Detective Chief Inspector Colin Boyle said: “This operation is part of long-term plan to tackle drugs use and supply throughout Scotland.
“Nisbet and his associates ran a drug empire throughout Scotland. Operation Lapstone did not just disrupt this empire – it dismantled it.
“The sale and use of illegal substances is a scourge on our community and is a top priority for Police Scotland. We will not tolerate this type of anti-social behaviour and we will continue to hold those who peddle drugs in our community to account and bring them to justice.”
Detective Inspector Graeme Naysmith added: “Serious Organised Criminals undermine the efforts of those that are trying to make an honest living.
“Police Scotland can be contacted on the non-emergency number 101 by anyone wishing to pass on information about those involved in organised crime and apparently living beyond their means. Information can also be given anonymously via Crimestoppers on 0800 555 111.”