The number of drugs including spice found by staff in Doncaster prisons has risen sharply over the last five years, according to official figures.
In the 12 months between March 2017 and March 2018, 221 searches in Doncaster prison uncovered drugs - up from 142 five years ago.
In the same time period, drugs were found during 74 searches within Hatfield prison.
At Lindholme prison, five times the amount of drugs were found in the 12 months from March 2017 when compared to five years ago. Drugs were found during 208 searches up until March 2018.
The biggest increase was at Moorland prison, where 13 times more drugs were found between March 2017 and March 2018 when compared to five years ago. During the time period, drugs were found during 133 searches.
For the first time this year, the figures include psychoactive substances such as spice, the abuse of which has increasingly become a concern for prison staff.
Andrew Neilson, the campaigns director at the Howard League for Penal Reform, said that the finds of drugs and other contraband, including mobile phones, were symptomatic of wider problems in the prison system.
He said: “The rising number of drugs and mobile phone confiscations is a symptom of the problems in an overburdened and under-resourced prison system that is failing the public.
“Where there is drug abuse there is also debt and violence, and these problems have become more severe in prisons across England and Wales as overcrowding and staff shortages have taken their toll.
“The best way to reduce the supply of drugs into prisons is to reduce the demand for them. This means ensuring that prisons are properly resourced and prisoners are occupied with purposeful activity, such as work, education, training and exercise.
“Above all, we need to see bold but sensible action to reduce the prison population. This would save lives, protect staff and prevent more people being swept away into deeper currents of crime and despair.”
The situation in Doncaster reflects the national picture, where 20 per cent of all drug tests carried out in prisons in England and Wales were positive, meaning more than 11,000 samples were returned showing drug use.