Christopher Edwards, on remand facing a public order charge, could be identified only by his dental records. He was killed on his first night in Chelmsford prison in 1994.
A three-year, pounds 1m inquiry uncovered multiple errors by the authorities, including the failure of prison officers to respond to Mr Edwards when he pressed the emergency call bell in his cell.
During checks at the prison last October, Sir David Ramsbotham, the chief inspector, tested the call bell system three times, and no prison officers responded.
In his report, he said: "The failure of staff to respond to call bells came in for severe criticism in the official inquiry into the murder of Christopher Edwards, by another prisoner, on his first night in prison. We looked to see whether that lesson had been learnt.
"We spent some time on the induction wing and tested the cell call system on three separate occasions. It was working but staff failed to answer any of the calls. This was totally unacceptable. Staff should respond to the cell call system and check the welfare of their prisoners frequently."
Sir David went on: "There can be absolutely no excuse for this, and I am staggered that, in view of what has happened, and of which staff allegedly were ashamed, it should still be the case. It must make me question staff's understanding of the Prison Service's own Statement of Purpose, and their determination to carry out their tasks in the way that the public has a right to expect of them."
Mr Edwards, who had a degree in Japanese and economics, was killed by Richard Linford, a paranoid schizophrenic who had been identified by doctors as a potential killer.
The chairman of the official inquiry said neither man should have been in prison and referred to a "needless and tragic loss of life" brought about by "astonishing" failures by health and social services.
Linford is now in Rampton special hospital. The parents of Christopher Edwards are seeking compensation for their son's death and taking their case to the European Court of Human Rights.
The director-general of the Prison Service, Richard Tilt, said: "I am concerned, as Sir David is, about the apparent failure of the cell call bell system.
"The governor of Chelmsford has now issued strict instructions to prisoners and staff, stressing the dangers of abusing the system and the importance of responding to alarms promptly."
Sir David was so concerned by the "fundamental" failings in management, cleanliness and health care at Chelmsford that he has promised to take the unusual step of returning in a year to see if improvements have been made.
He said: "The areas requiring immediate attention were reception, the induction programme, improvements to health care, the development of a young offenders' programme and the visits area."
The chief inspector said part of the problem was that the prison had four governors in four years.
He was also concerned by a lack of hygiene. Gutters were littered with pigeon corpses, walls were covered in stains of "organic origin" and food was prepared near a toilet.Reuse content