The number of prisoners disciplined for taking drugs in jail has nearly doubled over the past four years, according to Scottish Prison Service figures.
1,164 prisoners were caught either taking drugs or administering them to others during 2016/17, nearly double the 634 caught four years ago.
The figure, revealed in the SPS annual report for 2016/17, is the highest since 2008/09, when 1,257 such incidents were recorded.
Scottish Conservative shadow justice secretary Liam Kerr said: “Yet again, we see offenders continuing their criminality within prison walls, an environment which is supposed to be completely secure.
“For the second year running, more than three inmates are being caught using drugs every day, and these figures indicate it’s getting worse year after year.
“Detecting and recording these incidents isn’t enough – it’s crucial the SPS cracks down on this problem and stops these substances slipping through the net.
“All political parties agree that rehabilitation of offenders is critical if we want to reduce stubbornly high reoffending rates.
“But how can this be expected to take place while drug-taking remains so prevalent in prisons?”