Operation Hambo was launched following intelligence that drugs, in particular psychoactive substances, were being distributed in HMP Addiewell, with those responsible being helped by accomplices from outside the prison.
Police executed warrants at three addresses in Renfrew and Paisley, Renfrewshire, yesterday and today. There was significant activity at the prison in West Lothian.
Ten men, aged between 19 and 35 and from within the prison estate, and a further two men aged 34 from North Lanarkshire and Edinburgh were arrested along with three women aged 57, 34 and 27 from the Renfrewshire area.
Drugs recovered as part of the operation included psychoactive substances, heroin, cocaine, and synthetic and herbal cannabis.
Police said eight men within the prison estate were charged in connection with the possession of drugs. A further two were charged in connection with the sale and supply of drugs.
Three were also charged with mobile phone offences.
The three women were charged in connection with the sale and supply of drugs while the two men were charged in connection with the possession of drugs.
Superintendent Craig Smith said: “This successful operation is the result of extensive intelligence and evidence-gathering work conducted by our officers, staff within HMP Addiewell and colleagues at the Scottish Prison Service.
“I’d like to thank our partners for their dedication and support in tackling this issue.
“The proliferation of drugs within the prison estate is a serious issue which can severely hinder those individual’s chances of rehabilitation and addressing their offending behaviour.
“Tackling the misuse of drugs and their distribution is a top priority for Police Scotland.
“Rest assured that whenever such offences are brought to our attention, whether it’s in our communities or our prisons, we will work with the relevant organisations to bring those responsible to justice.”
Police Scotland said it was continuing to work closely with both Sodexo Justice Services, who operate HMP Addiewell, and the Scottish Prison Service.
Prison director Ian Whitehead said they would continue to adopt a multi-disciplinary approach to tackle the problem.
He said: “Police Scotland’s early recognition of the problems posed by psychoactive substances in prison and associated criminal activity has allowed us to develop a unique partnership approach, taking robust action against those who attempt to introduce drugs to prisons.”
Mr Whitehead added: “The safety of our staff remains our top priority.
“We will continue to support those within our care suffering from substance misuse issues while every possible action is taken against those who attempt to introduce illicit items to the prison and who take an active part in moving drugs within the establishment.”
Those arrested will be reported to the procurator fiscal.
Tom Fox, head of corporate affairs at the Scottish Prison Service, said: “We will continue to work with police and other agencies to address the problems caused by those trying to introduce contraband into prisons in Scotland.
“We devote a great deal of time and energy to tackling the problem of illicit drugs and other contraband entering the prison environment.”