More than 1500 mobiles and parts smuggled into jails
Scotland's justice secretary says many more have gone undetected in the last two years.
More than 1500 smuggled mobile phones and component parts have been detected by prison authorities in the last two years, the justice secretary has said.
Michael Matheson told Holyrood's justice committee it is not the full figure as "more will escape detection".
The justice secretary appeared before the panel of MSPs on Tuesday morning to outline the Scottish Government's plans to block mobile phone networks in prisons to make the devices useless.
Phones are already banned from the country's prisons but thousands are smuggled in, with many of them used to organise illegal activities such as drug dealing.
He told MSPs: "Let me be clear, the unauthorised use of mobile phones in prison presents a range of serious risks to the security of prisons and to the safety of the public.
"They can be used to plan escape or indiscipline, or to conduct serious organised crime, including drug imports and serious violence from behind bars."
Matheson added later: "The challenges posed by unauthorised mobile phones and their component parts into prison and young offenders institutions is not insignificant.
"Component parts such as SIM cards are easily concealed, while we may have been able to recover more than 1500 mobile phones or component parts since 2013, more will escape detection."
The justice secretary said the new regulations "will render them worthless and stop prisoners using those phones to engage in criminal activity from prison permanently".