Child visitors have already been banned from the wards at Ashworth special hospital in Merseyside, where patients' mail and telephone calls are being screened. The security plan is a response to the Fallon report, published in January, which found evidence that pornography was freely available in Ashworth's personality-disorder unit, where sex offenders played unsupervised with an eight-year-old girl.
Ashworth houses some of Britain's most notorious criminals, including the Moors murderer, Ian Brady. Mr Dobson had rejected calls for the closure of the "dysfunctional" hospital and instead gave managers four months to get their house in order. The Secretary of State for Health said that under the leadership of the chairman, Ian Pirnie, security had been stepped up, with child visitors banned from wards, mail and telephone calls monitored, all visitors to the hospital searched and regular searches carried out.
The Fallon report, which featured 58 recommendations, called for a network of small regional secure units to replace Ashworth and the other special hospitals at Rampton, Nottinghamshire, and Broadmoor, Berkshire.
But Mr Dobson said the three special hospitals would continue to be the "main providers of high-security services". He said pounds 5.7m was being invested in further security measures at Ashworth, with independent experts reviewing all security arrangements.
"The work to produce the action plan has already brought improvements," he added. "We now need to build on those improvements. So the action plan will make long-term changes to the organisation and management of the hospital recommended by the Fallon inquiry, designed to benefit both patients and the public. This will be backed up by further future investment. Many of the hospital staff worked very hard to improve the situation in the hospital and they will be given the help they need to provide top-quality treatment and care of all the patients."