A North East prison which holds some of the most dangerous criminals in the country is to be expanded, the Ministry of Justice has announced.
Frankland Prison holds the killers of Bradford Pc Sharon Beshenivsky
Planning permission has been granted to boost the capacity of Frankland Prison in County Durham to hold an extra 120 inmates - raising the number to 850.
But the Prison Reform Trust said money should be spent on cutting re-offending rates not extra prison places.
The Ministry of Justice said it was committed to creating more spaces.
Frankland Prison currently holds the two men jailed for the murder of Bradford Pc Sharon Beshenivsky and previously held serial killer Harold Shipman.
Imran Hussain, head of policy and communications at the Prison Reform Trust, said: "This will not solve the problem, the government's approach is wrong.
"Frankland has been expanded in 1998 and 2004, so if building more spaces were the answer we wouldn't be here now.
"We are locked in this conveyor belt to find more spaces but not looking at the impact at re-offending or looking at why these people are in there."
The move is part of a wider government policy to create thousands more prison places over the next few years, in a bid to combat overcrowding.
The Ministry of Justice said it was committed to its £1.2bn program to improve conditions and create space in Britain's jails.