Police and the Crown Prosecution Service last night insisted it was right to charge a senior nurse at Airedale General Hospital with the murder of three patients.

The joint statement followed the findings of an independent report which has concluded that Anne Grigg-Booth was unlikely to have set out to “deliberately harm them”.

Instead the inquiry has condemned bosses at the Steeton hospital for allowing systemic failures to operate between 2000 and 2002 in which senior night duty nurses were able to administer opiates without prescription.

And the hospital’s Trust has been further criticised for failing to be alert to the problem six years earlier when a patient died two hours after an intravenous injection of an opiate by a Night Nurse Practitioner (NNP).

The findings of the independent report by Yorkshire and Humber Strategic Health Authority into the deaths at the hospital, between 2000 and 2002, and the subsequent arrest of Grigg-Booth were published yesterday in a 5,000 word report.

The 52-year-old, who had worked at Airedale for 25 years, died of an overdose at her home in Nelson in 2005 as she awaited Crown Court trial on the murder charges as well as one charge of attempted murder and 13 counts of causing grievous bodily harm by administering drugs overdoses to 12 other patients.

The police case against her was then formally discontinued but last night the police and the CPS said: “It is, of course, a matter for the inquiry to come to its own conclusions but we are satisfied that the West Yorkshire Police investigation was thorough and the decision by the CPS to prosecute was the correct one.”

The SHA inquiry was not started until last year and its findings were made public at the Yorkshire and the Humber Strategic Health Authority headquarters in Leeds.

Facing the press was a panel made up of Bridget Fletcher, nursing manager at Airedale General Hospital, Jo Coombs, director of nursing at NHS Bradford and Airedale, Andrew Cato, medical director at Airedale, Eddie Kinsella, an inquiry team member and Professor Sue Proctor, chief of nursing at the SHA. It was revealed that none of the managers involved in the Grigg-Booth scandal were now working at Airedale NHS Trust.

Grigg-Booth was dismissed by the Trust along with a manager, two other NPNs were downgraded, another took early retirement and a second manager resigned.

The 200-page report emphasises that Grigg-Booth was not a rogue nurse in the mould of Beverly Allitt who murdered four children in hospital.

She and other NNPs who were administering drugs without a prescription were victims of a management systemic failure, it states.

Mr Kinsella said: “She should not be demonised because she and others believed they were acting with the authority of the board.

“There was a schism between what the board perceived to be happening at night and what was actually happening and that led to this tragedy.”

He was referring to the remarks in the report which state that “the most striking feature was in the disconnection between what was happening on the wards at night and what the board knew. The board had no idea”.

Mr Kinsella said that Grigg-Booth did everything in the open and made scrupulous records of the drugs she administered and on one occasion even wrote to a senior manager admitting that what she was doing was illegal.

The system was introduced as part of the Government’s New Deal policy to reduce the hours of junior doctors, leaving the hospital at night to be run by the NNPs who could telephone doctors for advice when necessary. It was recorded in 1996 that a patient died two hours after an NNP administered an opiate.

Six years later, the report reveals that the death of a patient two hours after an intravenous administration of an opiate, set off an investigation by the hospital trust and the eventual police probe.

The report concludes: “If this conduct were truly against hospital policy, it should have been picked up and stopped six years earlier, well before any of the incidents we have reviewed.”

It says the position now is “very different” from that between 2000 and 2002.

Mrs Fletcher said: “There are now no NNPs at Airedale and a 24-hour system has been introduced with highly-qualified nurses working on a 24-hour shift basis. There is no disconnection between what goes on during the day and at night.”

The hospital had been awarded Foundation Trust status which had helped to focus on improving systems and safety was now as good as it could be, she said.

“We hope this final stage of the process has now fully explained the details concerning each patient as well as the action of Sister Grigg-Booth, other staff and the Trust at the time eight years ago,” said Mrs Fletcher.

“The Trust has made significant improvements particularly since 2005 thanks to the enormous efforts of the Trust board and staff,” she added.

The report makes 11 recommendations including that the Trust should make time for periodic reviews to ensure systems and processes do not take precedence over patients.