THE number of prisoners developing a drug problem behind bars has more than doubled in the last five years, according to research published today by public-sector think tank Reform.

Its analysis shows that almost 15 per cent of prisoners report being drawn to illegal substances after going to jail.

The independent think tank reviewed the results of surveys with inmates carried out by prison inspectors between 2013/14 and 2018/19.

The findings suggest that the proportion of prisoners who said they had experienced this problem rose from around 6.4 per cent to about 14.8 per cent.

Prison officers’ union POA said that the findings “coincide with a period of austerity in the public sector which decimated staffing levels in our prisons.”

POA chairman Mark Fairhurst said: “Cuts have consequences and it comes as no surprise to the POA that drug abuse in our prisons is rife and on the rise.

“You cannot do justice on the cheap and until this government starts to listen to the real prison experts, front-line staff and the trade unions, little will change.”

The Ministry of Justice said it was investing £100 million in airport-style security, including X-ray body scanners, to prevent drugs from entering prisons.

But Campbell Robb, chief executive of the National Association for the Care and Resettlement of Offenders, said: “These latest figures show that not only are people with drug problems being sent to prison rather than being properly treated but that people actually develop drug addictions while in custody.

“This is a stark reminder that in far too many cases sending someone to prison is doing far more harm than good, and that our broken justice system must be fixed.”

Reform called on the government to carry out an urgent review to consider ending the use of short-term prison sentences.