A row has erupted over claims by Scottish ministers that a pilot scheme banning the sale of alcohol to under-21s resulted in a sharp fall in crime. Opponents say the conclusions are based on flawed data. Earlier this month the Scottish Executive trumpeted the results of the Stop the Supply experiment, held in selected Scottish towns between April and June, which it claimed had led to a 60% drop in serious assaults and 40% drop in breaches of the peace. Ministers claimed the statistics were evidence that raising the minimum age for buying alcohol in off licences to 21 would help cut crime if it were extended across the country. However, opposition parties have rejected the claims as “propaganda” after it emerged that, at the same time as the pilot, other initiatives were also running, including test purchasing, marked bottles, increased police patrols and a telephone ring-around system to alert shops to potential underage customers. Scottish Liberal Democrat health spokesman Ross Finnie described the claims as “bogus”, adding: “Clearly, crime rates have been reduced by increasing the burden of responsibility on off-sales licence holders and increasing the level of police supervision to monitor the experiment.” Professor Sheila Bird of the Royal Statistical Society called the Scottish government “naughty” for drawing conclusions based on an improperly conducted trial. She said the 60% fall in serious assaults represented a drop from five incidents to two and was “statistically insignificant”. “The way the results are being reported, it may not even be spin, it may be naivety,” she said.