Prison Service director general Martin Narey has replaced the director of Ashfield Prison and Young Offenders' Institution, and brought in Portland Prison governor Kevin Lockyer.

The action was taken after concerns that conditions had deteriorated badly at the institution, at Pucklechurch near Bristol.

There was concern Premier Custodial Services would "lose effective control" of the institution, which holds 300 child inmates and 100 juveniles.

I have great faith in Kevin and the rest of this team who have great expertise and experience with managing young offender institutions

Martin Narey, Director General of the Prison Service

Mr Narey said: "I have recently made three unannounced visits to Ashfield after repeated concerns were raised to me by the Prison Service monitors based at the prison and by senior staff who oversee the juvenile estate.

"What I found has concerned me greatly and I have decided to act swiftly to bring in a new governor.

"I found that standards of care and control of prisoners were not as high as I would expect them to be.

"I considered that the prison was unsafe for both staff and the young people detained there and that urgent action was required."

'Made safe'

Mr Narey said Mr Lockyer had been installed as governor of Ashfield with immediate effect.

He said: "He will be supported by two more Prison Service members of staff.

"I have great faith in Kevin and the rest of this team who have great expertise and experience with managing young offender institutions.

"My aim is that the prison should be made safe and constructive and that in due course we are able to hand management back to a director appointed by Premier."

Ashfield opened in November 1999 and is managed by Premier Custodial Services under a 25-year contact with the Prison Service.

The Criminal Justice Act 1991 gives the director general of the Prison Service, on the authority of the secretary of state, power to step in and appoint a governor.

'Steps taken'

The move can be taken if the prison director is thought to have "lost or is likely to lose effective control of the prison".

It is the first time the emergency measures have been implemented.

A spokesman for Premier said financial penalties were likely to be suffered by the company under the terms of its contract as a result of Mr Narey's intervention.

He said: "We recognise that the prison was not functioning at full efficiency and we had already taken steps to appoint a new director."

He said until that time they would give Kevin Lockyer full support.