Drones have been seen flying into Scottish prisons 22 times over the past two years.
New figures obtained through Freedom of Information laws show the total amount of times unmanned aerial vehicles (UAVs) were seen flying within the perimeter of jails.
On five of those occasions, packages containing drugs and mobile phones were intercepted.
The remaining figures of unmanned aircrafts are unexplained and are instances where drones have been identified within the prison perimeter but have not been recovered or identified as carrying anything suspicious.
The drones were spotted over seven jails: Barlinnie, Dumfries, Saughton, Grampian, Inverness, Perth and Polmont.
One package discovered being flown into Saughton, Edinburgh, in November 2016 contained 113g of heroin and 50 diazepam tablets as well as three mobile phones and three phone chargers.
Another, intercepted going into Inverness in May 2016, had 106 steroids, 89.5 diazepam tablets, 5.46g of cannabis and 2.5g of herbal cannabis.
A packet of 36 unnamed tablets was found at Barlinnie in Glasgow in October 2016, while two separate drones were found to be carrying a total of six mobile phones into HMP Perth in September last year.
Scottish Labour’s justice spokesman Daniel Johnson said: “Clearly any introduction of contraband into the prison system is wrong and must be stopped. The SNP government must ensure our prison service is properly funded and its workers are properly supported so that the public can have confidence in the justice system.”
The Scottish Prison Service (SPS) said officers are conscious of the potential for use of drones in smuggling contraband
A spokeswoman said: “The Scottish Prison Service is aware of the potential for drones or quad-copters to be used illegally and various methods are deployed to prevent contraband from entering our establishments.
“Anyone found attempting to smuggle contraband into our prisons will be reported to the police.”
A Scottish Government spokesman echoed that position. He said: “The Scottish Prison Service is responsible for the safety and security of prisons and, in liaison with partners, ensures that a range of methods are deployed to prevent or capture contraband entering these establishments.
“The SPS reports any persons found attempting to smuggle contraband to the police.”