Figures from the Prison Reform Trust show that in Leeds prison at Armley, 30% of the prisoners use drugs - the second highest figure in the country.

But Wakefield prison has one of the lowest number of positive tests.

The Prison Reform Trust says this is because local jails like Leeds take people direct from courts and reflect the level of drug use in the community

The report also reveals that Northallerton Young Offenders Institution had the second highest rate of serious assaults on prisoners and staff

Askham Grange in York, one of only two open prisons for women in the country, was among the safest jails.